What is 3D Printed Porous Tantalum?

The discovery of tantalum

Known as a “biophilic” metal, pure tantalum has been used in orthopedic medicine for more than 80 years. tantalum was discovered in ore by Swedish chemist Ekeberg in 1802 and named after Tantalus. tantalum was obtained in higher purity by the sodium reduction of Na2TaF7 by Rhodes in 1866.

porous tantalum

Subsequently, with its unique physicochemical properties and excellent biological inertness and biocompatibility, pure tantalum was first used in the field of orthopedics in 1940 and has been clinically used for 80 years, becoming another new biomaterial after titanium, which is widely used in oral implant placement, femoral head necrosis treatment, coronary artery stent placement, artificial acetabular prosthesis implantation, surgical suture production and other medical-related fields. A large amount of literature confirms that no adverse reactions have occurred with pure tantalum as human implants.

Biological and physicochemical properties of tantalum

1) Physical properties of tantalum

Pure tantalum is a gray, bright, hard metal with moderate hardness and good ductility, and can be drawn into tantalum wires thinner than a hair.

2) Mechanical properties

The difference between pure tantalum and the elastic modulus of bone tissue is large, which is not conducive to osseointegration. As a new type of orthopaedic implant material, porous tantalum has an interconnected internal structure and is interwoven longitudinally and horizontally. It has physical properties such as high porosity, low modulus of elasticity, and high surface friction coefficient.

In terms of mechanical properties, porous tantalum is superior to solid tantalum and other commonly used medical metal materials. Its special pore structure makes its elastic modulus between that of human cancellous bone and cortical bone, making it particularly suitable for bone replacement, joint replacement, and human tissue filling. It can provide mechanical strength while reducing stress shielding, facilitating stress transmission, facilitating bone shaping, and also has excellent osteoinductive properties, and is widely used in the field of orthopedics, and has achieved ideal results.

Compared with other porous materials, the friction coefficient of porous tantalum is 0.80 and 0.74 relative to the cancellous bone and cortical bone, respectively, which is 40% to 80% higher than that of traditional metallic materials. This helps to bond with the host bone interface and enhance the stability of the initial implantation.

3) Good corrosion resistance

At room temperature, tantalum will not react with hydrochloric acid, concentrated nitric acid or even aqua regia, and common inorganic salts will not corrode it. It is chemically extremely stable and resistant to all inorganic and organic acids except hydrofluoric acid, sulfur trioxide, hot concentrated sulfuric acid and alkalis.

4) Good biocompatibility

Unlike conventional medical metal materials, biological tissue grows on tantalum after a period of implantation, just as it does on real bone. This is why Tantalum is also known as a “pro-metal”.

5) Good bone bioactivity

The biologically active bone material interface is a hydroxyapatite layer rather than a connective tissue layer, and Tantalum itself has good bone bioactivity and stable biological inertness, which allows it to form a strong bone interface integration with bone.

Tantalum Applications

High clinical demand and large market size

The preparation of biocompatible bone scaffolds has been one of the hot topics of research in the medical field, and there are no less than 3 million cases of medical human bone implants in the USA every year, with prices reaching tens of thousands or even more than 100,000 yuan per case. According to EvaluateMedTech, orthopedic-related medical devices had global sales of $36.5 billion in 2017 and will reach $47.1 billion in 2024, with a compound annual growth rate of 3.7%.

Current orthopedic metal implant materials

The choice of medical human bone implant materials, the earlier application of materials are stainless steel, nickel-chromium alloy, nickel-titanium alloy, the last 2 or 3 years the trend is TC4 titanium alloy, these materials contain nickel, chromium, or aluminum, vanadium and other harmful elements, and because of its elastic modulus exceeds the human bone too much, the material and the human body affinity is low, prone to “bone non-stick “phenomenon. Medical experts and the market urgently need new non-toxic and non-hazardous new materials with good affinity to the human body to improve the current situation.

Porous tantalum advantages

(1) Perfect integration with the host bone interface: compared to the most commonly used titanium, tantalum is more biocompatible and has a better osseointegration capability.

(2) Unique bionic trabecular structure: Tantalum’s elastic modulus is closer to that of bone tissue, making it more suitable for bionic trabecular structure in the human body than other metals.

(3) Inducing rapid bone and vascular growth into It can promote the rapid growth of bone tissue and vascular tissue into the pores of porous tantalum, and its highly porous and supportive structure provides extensive space for bone growth, forming a good biological fixation, which can effectively solve the exothermic effect of bone cement and the impact on surrounding tissues, which is great clinical progress.

The above advantages make it show great clinical application value and application space in different sizes of orthopedic implants, and different parts of bone defects.

1) Application of porous tantalum in orthopedics

In clinical applications, porous tantalum printing can be applied to all small and medium-sized restorative products. For large-sized repair products, considering the high density of pure tantalum and the excessive weight of the printed implant prosthesis, multi-component gradient printing can be adopted, with porous tantalum used in the bone growing-in area and other metals such as titanium alloy, which is cheaper and lighter in quality, can be used in other areas.

With the continuous research on tantalum materials in recent years, several clinical trials have proven that new implants made of medical tantalum in combination with titanium and other metals can compensate for the shortcomings of other metal materials in terms of biocompatibility, bioactivity, and implant-bone bonding.

2) Tantalum coating – a new direction for orthopaedic applications

Tantalum metal has excellent corrosion resistance, and its coating on the surface of certain medical metal materials can effectively prevent the release of toxic elements and improve the biocompatibility of metal materials. Tantalum coatings meet the three elements of ideal bone graft materials, namely osteoconductivity, osteoconduction and osteogenesis, resulting in wider clinical applications and more flexible patient choices.

In addition, tantalum has also been used as an implant material in the restorative treatment of patients with missing teeth. Experiments have shown that conventional implants can absorb up to 30% of the loading energy during the loading process, while tantalum trabecular implants can absorb 50%-75%, which allows the implant to disperse the loading force to the surrounding bone during the long-term intraoral functional loading, avoiding stress concentration, while the higher friction coefficient provides good initial stability during implant placement, thus improving the dental implant bonding rate, especially in implant patients with poor bone quality.

The Ultimate Guide to Tantalum

Tantalum, a metallic element, is found mainly in tantalite and is symbiotic with niobium. Tantalum is moderately hard, ductile, and can be drawn into thin foil in the form of filaments. Its coefficient of thermal expansion is very small. Tantalum has excellent chemical properties and is extremely resistant to corrosion.

tracing tantalum

Although tantalum is highly resistant to corrosion, its corrosion resistance is due to the generation of a stable protective film of tantalum pentoxide (Ta2O5) on the surface. It does not react to hydrochloric acid or concentrated nitric acid, either under cold or hot conditions. It can be used to make evaporating vessels, etc. It can also be used as electrodes for electronic tubes, rectifiers, and electrolytic capacitors. It is also used in medical treatment to make thin sheets or threads to mend damaged tissues.

 

Chemical symbol Ta, gray metal, in the periodic table belongs to the VB group, atomic number 73, atomic weight 180.9479, body-centered cubic crystal, common chemical compound valence +5.

Tantalum was discovered by the Swedish chemist A.G. Ekeberg in 1802 and named tantalum after the Greek mythological figure Tantalus (Tantalus). 1903, the German chemist W. von Bolton prepared the first plastic metal tantalum for use as filament material. 1940, large-capacity tantalum capacitors appeared and were widely used in military communications.

In 1940, large-capacity tantalum capacitors appeared and were widely used in military communications. During the Second World War, the demand for tantalum increased dramatically, and after the 1950s, the demand for tantalum rose year by year due to its expanding applications in the capacitor, high-temperature alloy, chemical, and atomic energy industries, promoting the development of research and production of tantalum extraction processes.

The hardness of tantalum is low and correlates with the oxygen content; ordinary pure tantalum, in its annealed state, has a Vickers hardness of only 140 HV. It has a melting point of 2995°C and ranks fifth among the monomers, after carbon, tungsten, rhenium, and osmium. Tantalum is ductile and can be drawn into thin foils of the filament type. Its coefficient of thermal expansion is very small. It expands by only 6.6 parts per million per degree Celsius. In addition, it is very ductile, more so than copper.

 

Tantalum Chemical properties.

Tantalum also has excellent chemical properties and is extremely resistant to corrosion, not reacting to hydrochloric acid, concentrated nitric acid or “aqua regia” under both cold and hot conditions. However, tantalum can be corroded in hot concentrated sulfuric acid. Below 150°C, tantalum will not be corroded by concentrated sulfuric acid, but will only react above this temperature. At 250 degrees, the rate of corrosion increased to 0.116 mm per year, and at 300 degrees, the rate of corrosion was accelerated, and the surface was corroded by 1.368 mm after 1 year of immersion.

In the fuming sulfuric acid (containing 15% SO3) corrosion rate is more serious than in concentrated sulfuric acid, soaked in the solution at 130 degrees for 1 year, the surface is corroded by a thickness of 15.6 mm.

Tantalum is also corroded by phosphoric acid at high temperatures, but the reaction generally occurs at 150 degrees or more, and the surface is corroded by 20 mm when immersed in 85% phosphoric acid at 250 degrees for 1 year. In addition, tantalum can be rapidly dissolved in a mixture of hydrofluoric acid and nitric acid, and can also be dissolved in hydrofluoric acid. But tantalum is more afraid of strong bases.

In a caustic soda solution with a concentration of 40% at 110 degrees, tantalum will be dissolved rapidly, and in a potassium hydroxide solution with the same concentration, it will be dissolved rapidly for as long as 100 degrees.

Except for the above-mentioned cases, general inorganic salts generally cannot corrode tantalum below 150 degrees. Experiments have shown that at room temperature, tantalum does not react to alkaline solutions, chlorine gas, bromine water, dilute sulfuric acid, and many other agents, but only to hydrofluoric acid and hot concentrated sulfuric acid. This is a relatively rare occurrence among metals.

 

Tantalum has properties that make it very versatile. In equipment for the production of various inorganic acids, tantalum can be used as a replacement for stainless steel, with a life expectancy several dozen times longer than that of stainless steel.

In addition, in the chemical, electronic and electrical industries, tantalum can replace the tasks that used to be undertaken by the precious metal platinum, making the costs required much lower. Tantalum is manufactured into capacitors equipped into military equipment.

The United States has an exceptionally developed military industry and is the world’s largest arms exporter. Half of the world’s tantalum production is used in the production of tantalum capacitors, and the U.S. Department of Defense Logistics Agency is the largest owner of tantalum, having at one time bought out one-third of the world’s tantalum powder.

 

 

Tantalum is one of the rare metal mineral resources and is a strategic raw material indispensable for the development of the electronics industry and space technology.

 

Tantalum and niobium have similar physicochemical properties and are therefore co-occurring in minerals in nature. The classification of tantalum or niobium ore is mainly based on the content of tantalum and niobium in the mineral, which is called niobium ore when the niobium content is high and tantalum ore when the tantalum content is high.

Niobium is mainly used in the manufacture of carbon steel, super alloys, high-strength low-alloy steel, stainless steel, heat-resistant steel and alloy steel; tantalum is mainly used in the production of electronic primary devices and alloys.

Tantalum and niobium minerals are complex in form and chemical composition, which in addition to tantalum and niobium, often also contain rare earth metals, titanium, zirconium, tungsten, uranium, thorium, and tin.

The main minerals of tantalum are tantalite [(Fe, Mn)(Ta, Nb)2O6], heavy tantalite (FeTa2O6), fine crystal [(Na, Ca)Ta2O6(O, OH, F)], and black rare gold ore [(Y, Ca, Ce, U, Th)(Nb, Ta, Ti)2O6], etc. The waste residue of tin refining contains tantalum, which is also an important resource of tantalum.

 

Rare Watchmaking Metal – Tantalum

Within the world of watchmaking, there has always been an unquenchable thirst for material innovation. Over the past few decades, the arms race of the age of the new materials has given rise to countless alloys, each surpassing the others in terms of strength and durability.

Big Bang Tantalum

Technology continues to advance, prompting us to desperately tap into the potential of the periodic table of elements in search of the next exotic metal that can replace gold and titanium.

Today let’s learn about a new metal material for space: tantalum. Tantalum, a chemical element with the symbol Ta and atomic number 73, takes its name “Tantalum” from the Greek myth of Tantalus. With a core mass of 16.7 g/cm3, tantalum has a similar weight to 18-carat gold. A hard, blue-gray, rare transition metal, tantalum has a much harder surface than other metals used in watchmaking, such as stainless steel, gold and titanium. It is extremely resistant to corrosion.

Tantalum is a refractory metal with a melting point of 3017 °C (boiling point 5458 °C), only tungsten, rhenium, osmium, and carbon have a higher melting point than it. It is often used as a secondary component of alloys. Tantalum’s low chemical activity makes it resistant to acid corrosion, and it is even resistant to aqua regia at temperatures below 150 °C. It is a suitable substitute for platinum as a material for laboratory equipment. It has a characteristic blue color that lurks beneath a lustrous silver-tone, providing an invisible luster that no other metal, not even titanium, can achieve.

Tantalum’s unique physicochemical properties are what attract high-end luxury watches. Imagine a watch that is almost heavier than gold or platinum, with a distinctive blue/gray hue, while staying away from the exaggerated nature of gold. And with no signs of aging corrosion over the years! This rare space metal has so far only found its way into the product lines of a few fine watchmaking brands.

The use of tantalum in the watch industry

The body of an OMEGA watch is titanium, and the bezel and central double link of the watch are tantalum. The two metals are easier to distinguish: titanium is gray with a slight yellow tint, while tantalum is darker with a blue tint.

The Hublot Big Bang Tantalum has been a staple of Hublot’s line since its launch in 2005, and although it has been re-imagined in a dozen different material and color combinations, the Tantalum variant tops the list. The grey timepiece has a diameter of 44.5 mm, a case, lugs and bezel made of the rare metal tantalum, and a brushed dial that displays the time, date and chronograph functions. As with most Big Bang, Hublot seamlessly blends contrasting materials, combining a rustic, soft tantalum watch with a black rubber strap.

Girard-Perregaux Bi-Axial Tantalum & Sapphire Tourbillon Girard-Perregaux first introduced its lightweight titanium tourbillon biaxial tourbillon just one year after its tantalum case was born – a stunning hand-wound mechanical piece whose distinctive look defined it.

Can the Metal “Tantalum” be Used for Rings?

Can the metal “tantalum” be used for rings?

Yes, it can.

Tantalum is extremely resistant to corrosion and does not react to hydrochloric acid, concentrated nitric acid, or aqua regia in either cold or hot conditions.

tantalum rings

Tantalum’s pro-biological properties make it medically useful for making thin sheets or threads to mend damaged tissue. It is also harmless to the human body when made into rings and jewelry, and can be worn without worry.

Tantalum itself is harmless to humans and is as biophilic as silver, titanium, niobium, and other metals. However, tantalum and niobium may be mixed with rare earth elements during the smelting and extraction process, resulting in a little radioactivity, but pure tantalum is very safe.

Tantalum and niobium -a symbol of love?

Niobium and tantalum are in the same group in the periodic table and have very similar physical and chemical properties. In nature, they are often “inseparable”, like a pair of “twins”. When niobium and tantalum were discovered in the early 19th century, they were thought to be one element, and it was only after about 42 years that they were separated for the first time by chemical analysis, and it became clear that they were two different metallic elements.

Tantalum (Ta) niobium (Nb) are high melting point (tantalum 2996 ° C, niobium 2468 ° C), high boiling point (tantalum 5427 °C, niobium 5127 °C) rare metals, the appearance of steel-like, gray-white luster, powder dark gray, with gas absorption, corrosion resistance, superconductivity, unipolar conductivity and high strength at high temperatures, and other characteristics.

Therefore, the current tantalum niobium new material applications related to high-tech industrial fields include electronics, precision ceramics, and precision glass industry; electro-acoustic optical devices; cemented carbide, astronautics, and electronic energy industry; biomedical engineering; superconductivity industry; special steel and other industries.

Niobium-tantalum has good resistance to physiological corrosion and biocompatibility and does not interact with body tissues, so it is often used in the manufacture of bone plates, skull plate bone screws, dental implant roots, surgical appliances, etc. Tantalum is also known as a “biophilic metal” because it replaces bone in the human body with tantalum strips on which muscles can grow.

This is why they are also known as a “pro-biological metal”. Therefore, there are no allergies when using them for rings, and the price is better. Because tantalum is almost twice as dense as niobium, a tantalum ring of the same size will be more textured, darker in color, and more expensive than a niobium ring.

Because they have always coexisted in nature, we can also define them as a good brother or a loving couple, if you want to buy a pair of rings you can consider buying one each of tantalum and niobium, which has a better meaning!

Ten Metals with the Highest Melting Points on Earth!

Tungsten and tungsten wire bulbs have the highest melting points of all metals. In addition, do you know which metal elements have melting points?

highest melting points metal

This article will take a look at the top ten metals with the highest melting points.

Tungsten

Tungsten is a silvery-white metal shaped like steel. It has the highest melting point of any metal element, up to 3422°C, and a boiling point of 5927°C, making it the highest melting point in the world. It is an ultra-high temperature-resistant metal, ranking first in the list of metals with the highest melting points. As a rare high melting point metal, tungsten is commonly used as a lamp filament because when an electric lamp is turned on, the filament reaches temperatures of up to 3000°C. Only tungsten can withstand such high temperatures. In addition, tungsten increases the high-temperature hardness of steel. Meanwhile, tungsten is widely used in the alloy, electronic and chemical industries because of its high melting point, high hardness, high density, and good electrical conductivity. At present, more than 20 kinds of tungsten minerals and tungsten-bearing minerals have been found on the earth.

Rhenium

Rhenium is a silvery-white rare metal with a high melting point. It has the second highest melting point of all metals, second only to tungsten. Its melting point is as high as 3180℃ and its boiling point is 5900℃. Because of its high melting point, rhenium is more difficult to obtain than diamonds and is one of the rarest elements in the earth’s crust, making it very expensive and among the most expensive metals in the world. Rhenium and its alloys are widely used in the aerospace, electronics industry, petrochemicals, and other fields, especially in high-efficiency jet engines and rocket engines, and are therefore of great importance in military strategy.

high melting metal

Osmium

Osmium is a high-density rare metal, belonging to the heavy platinum group of metals, and is the world’s highest density metal. Osmium is found in osmium-iridium ores, which are extremely difficult to mine because of their density of 22.48 g/cm3, a high melting point of 3045°C, and a boiling point above 5027°C, making them one of the three metals with the highest melting points in the world. Osmium has a wide range of applications and can be used to make ultra-hard alloys. It is mainly used as a catalyst in the industry. It is often used to make products with other metals to extend their life.

Tantalum

Tantalum is a rare metal mineral resource found mainly in tantalite, which coexists with niobium. With a density of 16.68 g/cm³, a melting point of 2980°C, and a boiling point of 5425°C, it is the fourth most insoluble metal after tungsten, rhenium, and osmium. As a rare metal, tantalum has a high melting point, low vapor pressure, good cold processing performance, high chemical stability, and strong resistance to liquid metal corrosion, and has a wide range of application prospects. It has important applications in high-tech fields such as electronics, metallurgy, steel, chemical industry, cemented carbide, atomic energy, superconductivity technology, automotive electronics, aerospace, and medical and scientific research. Almost half of the world’s tantalum metal production is used to produce tantalum capacitors.

Molybdenum

Molybdenum is a transition metal element. It is an essential trace element for humans, animals, and plants. It is also the metal element with the highest melting point. It has a density of 10.2 g/cm³, a melting point of 2610°C, and a boiling point of 5560°C. Molybdenum is a silvery-white metal that is hard and tough. Like tungsten, it is a refractory and rare metal. According to worldwide molybdenum consumption statistics, molybdenum still occupies the most important position in the steel industry, accounting for about 80 percent of total molybdenum consumption, followed by the chemical industry, which accounts for about 10 percent. In addition, molybdenum is also used in medicine, agriculture, and electrical and electronic technology, which accounts for about 10 percent of total consumption.

Niobium

What metal has the highest melting point? Niobium is one of the metals with the highest melting point in the world. Niobium is a silvery gray, soft, and ductile rare high melting point metal with a density of 8.57 g/cm³, a melting point of 2477°C, and a boiling point of 4744°C. At room temperature, niobium does not react with air, but at high temperatures, it combines directly with sulfur, nitrogen, and carbon. Niobium has good superconductivity, corrosion resistance, high melting point, and wear resistance and is widely used in steel, superconducting materials, aerospace, electronics industry, medical, and other fields. Niobium does not occur in nature in its pure state but is combined with other elements to form minerals. Brazil and Canada are still the largest producers of niobium concentrates.

Iridium

Iridium is extremely chemically stable in acids and is insoluble in acids. It is the most corrosion-resistant metal and the metal material with the highest melting point. Its density is 22.56 g/cm³, melting point 2450°C, and boiling point 4130°C. The amount of iridium in the earth’s crust is 1/10 million. It is often dispersed in various ores of alluvial deposits and alluvial mines together with platinum-based elements. It is rare precious metal material and belongs to the platinum family of metals. Iridium can be used in a wide range of industrial and medical applications due to its high melting point, high hardness, and corrosion resistance.

Ruthenium

Ruthenium is one of the platinum group metals. It is the least abundant of the platinum group elements in the earth’s crust and the last of the platinum group elements. Ruthenium is a rare transition metal with stable properties and high corrosion resistance, with a melting point of 2310°C and a boiling point of 3900°C, making it the highest melting point metal material in the world. It has a variety of uses and is commonly used in electronics. It is cheaper than rhodium, has very similar properties, and is commonly used to produce electrical contacts, wires, and electrodes.

Hafnium

Hafnium is a shiny silver-gray transition metal with a density of 13.31 g/cm³, a melting point of 2233°C, and a boiling point of 4603°C. It is one of the metals with the highest melting point on earth and ranks ninth among the metals with the highest melting point. in 1925, the Swedish chemist Hedwig and the Dutch physicist Kost obtained pure hafnium salts by stepwise crystallization of fluorine-containing complex salts and reduction with sodium metal to obtain pure Hafnium metal. Hafnium is rarely found in the earth’s crust and usually coexists with zirconium. Hafnium is used as an atomic energy material, alloy material, high-temperature resistant material, electronic material, etc. because of its high-temperature resistance, oxidation resistance, corrosion resistance, ease of processing, rapid heat absorption, and exotherm.

Technetium

What is a high melting point metal? Technetium is one of the metals with the highest melting point on earth, with a melting point of 2157℃ and a boiling point of 4265℃. Technetium is also the first element prepared by artificial methods. It was first obtained by bombarding molybdenum with deuterium (heavy hydrogen) in a cyclotron. The element symbol is TC. it belongs to group VIIB of the periodic table and the element is a silvery-white metal. Technetium is used as a tracer in metallurgy, low-temperature chemistry, corrosion-resistant products, nuclear fuel burn-up measurements, and medical research.

Rhodium

Rhodium is a silvery-white, hard metal that belongs to the platinum family of elements. It is also the most expensive precious metal in the world and is extremely rare. Rhodium has a higher melting point than platinum, with a melting point of 1966°C and a boiling point of 3727°C. Rhodium is insoluble in most acids, has a high melting point, and is surprisingly resistant to corrosion. This silver metal is commonly used because of its reflective properties. In addition to making alloys, it is also used as a bright and hard coating for other metals. However, due to the high price of rhodium, it is usually used only as an additive element, except for special applications.

Vanadium

Vanadium is a silvery-white metal and has one of the highest melting points of any metallic element. With a melting point of 1890°C and a boiling point of 3380°C, it has the element symbol v and belongs to the VB group in the periodic table of elements. It is known as a refractory metal along with niobium, tantalum, tungsten, and molybdenum. Among the properties of vanadium, it rarely forms as a stand-alone mineral and is mainly found in vanadium-titanium magnetite. However, world reserves of vanadium and titanium magnetite are enormous and are concentrated in a few countries and regions such as Russia, South Africa, Australia, and the United States. Vanadium is widely used in the metallurgical, aerospace, chemical, and battery industries in the form of ferrovanadium, vanadium compounds, and vanadium metal.

Why is Tantalum So Expensive?

Because of the characteristics of tantalum such as good cold working and welding performance, tantalum has been used in electronics, semiconductor, chemical, machinery, aerospace, medical, and other industries.

tantalum metal

Why is Tantalum So Expensive?

Tantalum is a metal element with atomic number 73 and the chemical symbol Ta, the element corresponds to the steel gray metal, which has extremely high corrosion resistance, both in cold and hot conditions, and does not react to hydrochloric acid, concentrated nitric acid and “aqua regia”.

Tantalum is mainly found in tantalite and is symbiotic with niobium. Tantalum is moderately hard, ductile and can be drawn into thin foils of the filament type. Its coefficient of thermal expansion is very small.

Tantalum has very high chemical properties and is extremely resistant to corrosion. It can be used to make evaporating vessels, etc. It can also be used to make electrodes for electronic tubes, rectifiers and electrolytic capacitors. It is used medically to make thin sheets or threads to mend damaged tissue. Although tantalum is highly resistant to corrosion, its resistance to corrosion is due to the generation of a stable protective film of tantalum pentoxide (TaO) on its surface.

Smelting: Tantalum-niobium ores are often accompanied by a variety of metals, and the main steps in tantalum smelting are decomposition of the concentrate, purification and separation of tantalum and niobium to produce pure compounds of tantalum and niobium for the metal. Ore decomposition can be used hydrofluoric acid decomposition method, sodium hydroxide melting method and chlorination method, etc. Tantalum and niobium separation can be used solvent extraction method [commonly used extractants are methyl isobutyl ketone (MIBK), tributyl phosphate (TBP), secoctanol and acetamide, etc.], step-by-step crystallization method and ion exchange method.

Separation: First, the tantalum-niobium iron ore concentrate with hydrofluoric acid and sulfuric acid decomposition of tantalum and niobium is fluorotantalic acid and fluoronobotic acid dissolved in the leaching solution, while iron, manganese, titanium, tungsten, silicon and other associated elements are also dissolved in the leaching solution, forming a very complex composition of strong acidic solution. The tantalum-niobium leach solution is extracted with methyl isobutyl ketone and extracted into the organic phase at the same time. The pure organic phase containing tantalum-niobium is back-extracted with dilute sulfuric acid solution to obtain the organic phase containing tantalum.

Niobium and a small amount of tantalum enter the aqueous phase and then the tantalum is extracted with methyl isobutyl ketone to obtain a pure niobium-containing solution. The pure tantalum-containing organic phase is back-extracted with water to obtain a pure tantalum-containing solution.

The organic phase after the reverse extraction of tantalum is returned to the extraction cycle. Pure tantalum fluoride solution or pure niobium fluoride solution reacts with potassium fluoride or potassium chloride to form potassium tantalum fluoride (KTaF) and potassium niobium fluoride (KNbF) crystals, respectively, and can also react with ammonium hydroxide to form tantalum or niobium hydroxide precipitates.
Tantalum or niobium hydroxide is calcined at 900~1000°C to produce tantalum or niobium oxide.

Preparation of tantalum

Tantalum metal powder can be produced by the thermal reduction of metal (sodium thermal reduction) method. The reduction of potassium fluorotantalate with sodium metal in an inert atmosphere: K2TaF7+5Na─→Ta+5NaF+2KF. The reaction is carried out in a stainless steel tank, and the reduction reaction is completed rapidly when the temperature is heated to 900°C. The tantalum powder made by this method is irregular in particle shape and fine in size, which is suitable for making tantalum capacitors.

Tantalum metal powder can also be made by electrolysis of molten salt: using the molten salt of potassium fluorotantalate, potassium fluoride and potassium chloride mixture as the electrolyte to dissolve tantalum pentoxide (Ta2O5) in it, and electrolysis at 750℃, tantalum powder of 99.8~99.9% purity can be obtained.

Reduction of Ta2O5 with carbon heat can also be obtained from tantalum metal.

Reduction is generally carried out in two steps: first, a certain ratio of Ta2O5 and carbon mixture in the hydrogen atmosphere at 1800 ~ 2000 ℃ to make tantalum carbide (TaC), and then TaC and Ta2O5 in a certain ratio of the mixture of vacuum reduction into tantalum metal. Tantalum metal can also be produced by thermal decomposition or hydrogen reduction of tantalum chloride.

Dense tantalum metal can be prepared by vacuum arc, electron beam, plasma beam melting or powder metallurgy. High-purity tantalum single crystals are produced by crucible-free electron-beam regional melting.

Tantalum is a metallic element with an atomic number of 73 and the chemical symbol Ta, which corresponds to a steel-gray metal with extremely high resistance to corrosion, both in cold and hot conditions, and does not react to hydrochloric acid, concentrated nitric acid or “aqua regia”.

Tantalum is mainly found in tantalite, which is symbiotic with niobium. Tantalum is moderately hard, ductile and can be drawn into thin foil in the form of filaments. Its coefficient of thermal expansion is very small. Tantalum has very high chemical properties and is extremely resistant to corrosion. It can be used to make evaporating vessels, etc. It can also be used to make electrodes for electronic tubes, rectifiers and electrolytic capacitors.

It is used medically to make thin sheets or threads to mend damaged tissue. Although tantalum is highly resistant to corrosion, its resistance to corrosion is due to the generation of a stable protective film of tantalum pentoxide (TaO) on its surface.

What Products are Made of Tantalum?

Tantalum appears in many applications, including

– Sputtering barrels: Computer disk manufacturers and other industries that use sputtering processes are increasingly using tantalum to resist corrosion in sputtering barrels. The tantalum lining process is more environmentally friendly than chromium lining, helping the industry reduce its ecological impact.

tantalum

– Machined fasteners: Machined fasteners made from tantalum offer excellent corrosion resistance. They replace fasteners made from alternative materials that are prone to failure or require expensive equipment downtime for maintenance. Tantalum fasteners are found in industries such as mining, energy, and pharmaceuticals, as well as in metal and chemical processing.

– X-ray/radiation shielding: Tantalum’s radiopaque properties make it ideal for X-ray and shielding applications that seek to prevent radiation leakage. Tantalum shielding can also protect sensitive electronic components in aerospace structures as well as components operating in corrosive environments.

– Vacuum furnace heating elements: Many vacuum furnace components contain tantalum rods due to tantalum’s oxidation resistance and high melting point. Tantalum’s temperature particle stability increases the life expectancy of the machine, as it can withstand high temperatures for extended periods of time.

– Machined parts for chemical processing equipment: Tantalum’s corrosion-resistant properties make it the material of choice for machined parts for chemical processing equipment. Tantalum machined parts replace inferior materials that perform poorly in harsh chemical environments and require extensive maintenance.

 

The uses of tantalum

– 1: Tantalum carbide, used for cutting tools

– 2: Tantalum lithium, for surface acoustic waves, cell phone filters, hi-fi, and TV

– 3: Tantalum oxide, used in telescopes, cameras, lenses for cell phones and X-ray films, inkjet printers

– 4: Tantalum powder, used for tantalum capacitors in electronic circuits

– 5: Tantalum plate, used in chemical reaction equipment such as coating, valves, etc.

– 6: Tantalum wire, tantalum rod, used for repairing skeleton plates, suture frames, etc.

– 7: Tantalum ingots: used for sputtering targets, high-temperature alloys, computer hardware drive discs, and TOW-2 bomb-forming projectiles

 

Together with tungsten carbide WC and titanium carbide TIC, tantalum carbide TAC is a cemented carbide component used in cutting and drilling tools.

 

Tantalum is particularly suitable for heat exchangers; it has high thermal conductivity and its surface properties prevent the formation of adhesive deposits.

 

Manufacture of furnace components such as screens, supports, and crucibles. The alloying elements in high-temperature alloys increase high-temperature strength. It is biologically inert and can be used for implants, needles, etc. Yttrium tantalate YTAO4 is used in medical diagnostics.

 

SAM offers our customers a wide selection of tantalum rods, tubes, sheets, and wires, all designed for a variety of applications. Our products are cold rolled and annealed in a proprietary process to create machined parts with metallurgical properties ideal for applications such as sputtering gun tubes, processing into fasteners, X-ray radiation shielding, development rings, vacuum furnace heating elements, chlorinator springs, assemblies, and more for light bulbs or chemical processing equipment.

Tantalum Capacitors in the Military Industry

Why is tantalum so popular?

The most important use of tantalum is the manufacture of electronic components, especially capacitors. 50%-70% of the world’s tantalum is used to manufacture tantalum capacitors, mainly in the form of capacitor-grade tantalum powder and tantalum wire.
Because tantalum forms a dense, stable, amorphous oxide film with high dielectric strength on its surface, it forms a stable anodic oxide film in acidic electrolytes and is easy to process.

tantalum capacitors

At the same time, tantalum powder sintered blocks can obtain a large surface area in a small volume, so tantalum capacitors have a series of excellent properties such as high capacitance, low leakage current, and low equivalent series resistance, good high and low-temperature characteristics, and long service life.

Tantalum Capacitors in the Military Industry

A tantalum capacitor is called a tantalum electrolytic capacitor, which is also a kind of electrolytic capacitor, using tantalum metal as the dielectric, hence the name.

The tantalum capacitor was firstly developed by Bell Labs in 1956, and it is a passive component with a small volume and large capacity capacitor.

Tantalum capacitors’ downstream applications can be divided into two categories: military and civilian. The military field includes aviation, spaceflight, ships, weapons, and electronic countermeasures, while the civil field includes consumer electronics, industrial control, electric power equipment, new energy, communication equipment, rail transportation, medical electronics, and automotive electronics. As an essential basic electronic component in electronic circuits, capacitor products are widely used in the military and civilian fields.

Military capacitors are mainly ceramic capacitors and tantalum capacitors. The development of the military electronics industry is especially important in the context of the information-based military. It is widely used in communications, computers, automobiles, electrical appliances, aerospace, national defense, and other industrial and scientific sectors.

What Products is Tantalum Powder Used in?

Properties of Tantalum Powder

Tantalum powder is the powder state of tantalum metal. The chemical symbol Ta, a steel gray metal, belongs to the VB group in the periodic table, atomic number 73, atomic weight 180.9479, body-centered cubic crystal, common valence +5.

ta powder

Tantalum’s hardness is low and related to the amount of oxygen, ordinary pure tantalum, the annealed state of Vickers hardness is only 140HV .

It has a melting point of 2995°C and ranks fifth among the monomers, after carbon, tungsten, rhenium, and osmium. Tantalum is ductile and can be drawn into thin foils of the filament type. Its coefficient of thermal expansion is very small. It expands by only 6.6 parts per million per degree Celsius. In addition, it is very ductile, even more so than copper.

What are the types of Tantalum metal powder?

Tantalum metal powder is generally divided into nano tantalum powder, micron tantalum powder, high purity tantalum powder, spherical tantalum powder, etc.”

How to Manufacture Tantalum Powder?

“To make materials, the key is to rely on technical precipitation and accumulation.” Talking about the development process of spherical tantalum powder, Stanford Advanced Materials has been developing the technology for nearly 10 years since 2009.”

What Products is Tantalum Powder Used in?

The manager took the staff on a tour of the generation to three generations of powder-making equipment, as well as the latest dedicated powder-making machine for refractory metals, “We completed a breakthrough in the core technology of aerosolization of filamentous materials in 2015 and have been iteratively developing according to changes in the market for cutting-edge applications, from nano-powders, conventional 3D printing micron powders to the current refractory metal powders. ”

“The biggest challenge in R&D is to match with market demand, SAM focuses on high-end fields and finds cutting-edge application scenarios. We successfully docked with a U.S. military-civilian integration institute to fit their needs and customize the product.” The manager came to the product center, and we finally saw the real face of this cutting-edge material.

When we first picked up the bottle of metal powder in our hands, we immediately felt that the powder was very heavy, and when we gently shook it, we felt the powder undulate and flow with it like water – this is the special tantalum powder for 3D printing made by Stanford Advanced Materials. “Our loose packing density is very high, reaching 9.84g/cm3, which is close to 60% of the density of tantalum metal block, so although the bottle is small, it still feels very heavy in the hand. At the same time, this powder flows very well, so you will feel like water, and flows very smoothly. On the other hand, the physical property of high sphericity in the particle size range of ultra-fine powder makes the powder have better dispersion and larger specific surface area, which makes the powder more stable and excellent to use.”

“During the R&D process, we overcame two major challenges: first, to ensure high sphericity with effective particle size control; second, to solidify the process to achieve stable and efficient industrial mass production.” The manager of Stanford Advanced Materials said, “We have explored and improved our own powder-making process and developed a new generation of special models; we have verified and standardized many aspects such as raw materials, process parameters, and operating procedures.”

Porous Tantalum in Orthopedics

The preparation of biocompatible bony scaffolds has been one of the hot topics of research in the medical field. According to EvaluateMedTech, orthopedic-related medical devices had global sales of $36.5 billion in 2017 and will reach $47.1 billion in 2024, representing a compound annual growth rate of 3.7%.

porous tantalum

Current orthopedic metal implant materials

The choice of medical human bone implant materials, the earlier application of materials are stainless steel, nickel-chromium alloy, nickel-titanium alloy, the last 2 or 3 years the trend is TC4 titanium alloy, these materials contain nickel, chromium, or aluminum, vanadium and other harmful elements, and due to its elastic modulus exceeds the human bone too much, the material and the human body affinity is low, prone to “bone non-stick “phenomenon. Medical experts and the market are in urgent need of new non-toxic and non-hazardous new materials with good affinity to the human body to improve the current situation.

Multiple implant sizes, different clinical application scenarios

Porous tantalum has many advantages such as:

(1) Perfect integration with the host bone interface: compared to the most commonly used titanium, tantalum metal is more biocompatible and has a better osseointegration capability.

(2) Unique bionic trabecular structure: Tantalum’s elastic modulus is closer to that of bone tissue, which makes it more suitable for bionic trabecular structure in the human body than other metals.

(3) Inducing rapid bone and vascular growth into it can promote rapid growth of bone tissue and vascular tissue into the pores of porous tantalum, and its highly porous and supportive structure provides extensive space for bone growth, forming a good biological fixation, which can effectively solve the exothermic effect of bone cement and its effect on surrounding tissues, which is great clinical progress.

The above advantages make it show great clinical application value and applicability in different sizes of orthopedic implants, and different parts of bone defects.

porous tantalum application

1) Application of porous tantalum in orthopedics

In clinical applications, porous tantalum printing can be applied to all small and medium-sized restorative products. For large-sized repair products, considering the high density of pure tantalum and the excessive weight of the printed implant prosthesis, multi-component gradient printing can be adopted, with porous tantalum used in the bone growing-in area and other metals such as titanium alloy, which is cheaper and lighter in quality, being used in other areas.

With the continuous research on tantalum materials in recent years, several clinical trials have proven that new implants made of medical tantalum in combination with titanium and other metals can compensate for the shortcomings of other metal materials in terms of biocompatibility, bioactivity, and implant-bone bonding.

2) Tantalum coating – a new direction for orthopaedic applications

Tantalum metal has excellent corrosion resistance, and its coating on the surface of certain medical metal materials can effectively prevent the release of toxic elements and improve the biocompatibility of metal materials. Tantalum coatings can meet the three elements of the ideal bone graft material, namely osteoconduction, and osteogenesis, resulting in wider clinical applications and more flexible patient choices.

In addition, tantalum has also been used as an implant material in the restorative treatment of patients with missing teeth. Experiments have shown that conventional implants can absorb up to 30% of the loading energy during the loading process, while tantalum trabecular implants can absorb 50%-75%, which allows the implant to disperse the loading force to the surrounding bone during the long-term intraoral functional loading, avoiding stress concentration, while the higher friction coefficient provides good initial stability during implant placement, thus improving the dental implant bonding rate, especially in implant patients with poor bone quality.

Conclusion

Although porous tantalum is an ideal material for orthopaedic implants. However, due to the variability of the human body and the random morphology of bone defect sites, such as patients with bone tumors and patients with bone deformities, standardized porous tantalum can no longer meet the requirements of individual patient treatment. From the perspective of the development trend of clinical medicine, the best treatment method should be personalized treatment and the best implant should be a personalized implant.