Overview of Tantalum’s Main Products & Applications

Tantalum has a series of excellent properties such as high melting point, low vapor pressure, good cold workability, high chemical stability, strong resistance to liquid metal corrosion, and large dielectric constant of the surface oxide film. Therefore, tantalum is mainly used in high-tech fields such as electronics, metallurgy, steel, chemicals, hard alloys, atomic energy, superconducting technology, automotive electronics, aerospace, medical health, and scientific research.

tantalum capacitors

50% -70% of tantalum in the world is used to make tantalum capacitors in the form of capacitor-grade tantalum powder and tantalum wire. The surface of tantalum can form a dense and stable amorphous oxide film with high dielectric strength, which is easy to accurately and conveniently control the capacitor’s anodizing process.

Tantalum powder sintered blocks can obtain a large surface area in a small volume, so tantalum capacitors have high capacitance, low leakage current, low equivalent series resistance, and good high and low-temperature characteristics, long service life, and excellent comprehensive performance. Tantalum capacitors are widely used in industrial and scientific and technological sectors such as communications (exchanges, mobile phones, pagers, fax machines, etc.), computers, automobiles, home, and office appliances, instrumentation, aerospace, defense, and military.

Tantalum is an extremely versatile functional material. The following are the main products and applications of tantalum.

Tantalum carbide

Application: Cutting tools

Properties: Tantalum carbide is easy to form at high temperatures to avoid texture

Tantalum lithium

Application areas: surface acoustic waves, mobile phone filters, hi-fi and TV

Properties: strengthen the electronic signal wave, output more clear audio and video

Tantalum oxide

Applications: Lenses for telescopes, cameras and mobile phones, X-ray films, inkjet printers

Properties: Adjust the refractive index of optical glass, reduce X-ray exposure, improve image quality, and improve the wear resistance of integrated capacitors in integrated circuits

Tantalum powder

Applications: Tantalum capacitors in electronic circuits, medical devices, automotive parts such as ABS, airbag activation, engine management modules, GPS, portable electronics such as laptops, mobile phones, other devices such as flat-screen TVs, battery chargers, power diodes, Oil well probe, mobile phone signal shielding mast

Properties: high reliability, low failure rate, strong electronic storage capacity, it can withstand low temperatures such as -55 ℃ and high temperatures + 220 ℃, as well as severe vibration forces

Tantalum plate

Applications: Chemical reaction equipment such as coatings, valves, internal heat exchangers, cathodic protection systems for steel structures, water tanks, corrosion-resistant fasteners such as screws, nuts, and bolts

Properties: excellent corrosion resistance

Tantalum wire and tantalum rod

Applications: Tantalum wire and tantalum rod are used to repair hip joints, skull plates, bones after receiving tumor damage, suture clips, stent blood vessels

Properties: strong biological compatibility

Tantalum-artificial-joint

Tantalum wire and tantalum rod

Application: High-temperature furnace parts

Properties: The melting point is as high as 2996 ℃ (but vacuum protection is required)

Tantalum Disc

Application: sputtering target

Properties: a thin layer of tantalum, tantalum nitride coating oxide or semiconductor prevents copper migration

Tantalum ingot

Application: Superalloys such as jet engine vortex discs (such as blades)

Properties: The alloy composition contains 3~11% tantalum provides corrosion-resistant hot gas and allows higher operating temperature

Tantalum ingot

Application: Computer hardware driver CD

Properties: An alloy containing 6% of tantalum has shape memory properties

Stanford Advanced Materials supplies high-quality tantalum products to meet our customers’ R&D and production needs. Please visit https://www.samaterials.com/ for more information.

Super Performances of Tantalum in the Electronics & Aerospace Industries

Tantalum has a series of excellent properties, such as high melting point, low vapor pressure, good cold processing performance, high chemical stability, as well as strong resistance to liquid metal corrosion, etc., it has important applications in high and new technology fields such as electronics, metallurgy, superconducting technology, automobile electronics, aerospace, medical treatment, and scientific research. The following is a brief introduction to the superb performances of tantalum in the electronics and aerospace industries.

tantalum powder

Electronics industry

In the electronic industry, tantalum is mainly used as tantalum capacitors, which are usually used in the form of capacitor-grade tantalum powder, tantalum wire, and tantalum foil. A tantalum capacitor is one of the indispensable electronic components of radar, aerospace aircraft and missiles, and it is widely used for civil use, such as mobile communication, electronic equipment, and instruments.

As the specific surface area of tantalum powder is large, the dielectric constant of the thin film of the dielectric body is large, so the capacitance is large, then the small large-capacity capacitors can be made. The electrolytic capacitors made of tantalum have the advantages of small size, lightweight, good reliability, wide operating temperature range, and long service life.

Tantalum electrolytic capacitors can be classified into solid electrolytic capacitors and liquid electrolytic capacitors, and they are mainly divided into two anode types: foil anode and sintered anode. Tantalum wire is used as the anode lead for both capacitors.

With the development of the electronic industry, the miniaturization and high reliability of tantalum capacitors are becoming increasingly strict. At present, the international commercial specific capacity of tantalum powder has reached more than 150,000 mu.F•V/g, and the laboratory has reached 30,000 mu.F•V/g.

Tantalum is also used as a material for electron tubes. Due to its high melting point, low real gas pressure, good processing performance, small linear expansion coefficient, and good inspiratory property, tantalum is a good material for launching tube and high-power electron tube parts.

Besides the above, tantalum target is an important material for magnetron sputtering coating of electronic chips due to its high chemical stability. You may check out more information at the specialized target website.

Aerospace industry

In addition to a large number of tantalum capacitors used in the aerospace industry, tantalum is also mainly used in high-temperature alloy and tantalum matrix heat-resistant alloy in the aerospace industry, especially in engines. High-performance alloys such as superalloy, corrosion-resistant alloy, and wear-resistant alloy can be made by adding tantalum to nickel base, cobalt base, and iron-base alloys.

Compared with niobium superalloy, tantalum superalloy has superior performance, higher heat resistance, and greater stress load. These alloys are mainly used as heat-resistant and high-strength structural materials for supersonic aircraft, solid propellant rockets, and missiles, as well as parts for control and adjustment devices. For example, the combustion chamber of the American Ajina Spacecraft is made of ta-10w alloy, and the flame temperature is very high (up to 2760℃) when its cover is small.

The aerospace industry is the second largest user of niobium and tantalum. Niobium and tantalum alloys, especially their superalloys and heat-resistant alloys based on them, are indispensable supporting materials for hot components of aircraft jet engines, rockets, spacecraft, and other vehicles.

Stanford Advanced Materials supplies high-quality tantalum products to meet our customers’ R&D and production needs. Please visit https://www.samaterials.com/ for more information.

A Brief History of Tantalum

In 1801, Charles Hatchett, a British chemist, analyzed a collection of minerals preserved in British museums and discovered a new element, Columbium (later renamed Columbium), in honor of Colombia, where the ore was made. In 1802, Anders Gustav Ekberg, a Swedish chemist, crystallized tantalum from niobium in Scandinavia.

tantalum

Because tantalum and niobium have very similar properties and specific gravity, many scientists at the time mistakenly believed that the two elements were the same substance. In 1844, German chemist Rosser used chemical methods to prove that tantalum and niobium are two elements.

In 1903, pure tantalum was produced for the first time. Tantalum capacitors manufactured with tantalum, with high capacity, small size, and high reliability, are still irreplaceable components in the electronics industry.

With the continuous miniaturization and portability of global electronic products since 1990, tantalum capacitors have been widely used. Today, tantalum capacitors are shipped about 100 billion times a year.

There are three major Tantalum companies operating in the world today: the US Cabot group, the German HCST group, and China Swing Orient Tantalum Industry Co., Ltd. These three companies produce more than 80 percent of the world’s tantalum products.

Tantalum used in electronics accounts for 60% of total production. But tantalum is not just used as a capacitor. Nickel-tantalum alloy is widely used in advanced aero-engine blades.

Before 2007, the world’s major sources of tantalum were Australia and Brazil. In 2000, the world’s major producing countries produced approximately 1,100 tons of tantalum concentrate, of which Australia accounted for 45%, mainly at Greenbush and Wodgina mines, while Brazil accounted for 17%, Rwanda 12%, and Congo 9%. At the time, Congo was in the midst of a second civil war, and large numbers of rebels smuggled Congolese tantalum mines into Rwanda for export under the Rwandan name.

In 2003, the Democratic Republic of Congo (DRC) signed a peace agreement with rebels in the east that ended a second civil war. But the rebels in eastern DRC have not really laid down their arms, and are no longer engaged in open, large-scale fighting with government forces. The rebels continue to splinter and regroup, with new rebels popping up every now and then. Congo and the surrounding great lakes countries are backward industrially, all guns and ammunition are imported, and any imports must be accompanied by foreign currency. Both the rebels and the great lakes countries are eyeing tantalum as a new source of revenue.

Tantalum has supported the fighting in eastern Congo. Subsequently, the world’s major tantalum deposits have undergone a stunning reversal. Cheap Labour in eastern Congo, using baskets and hammer shovels, has been digging holes in droves, defeating Australian tantalum miners armed with big mining machines. Australia’s tantalum mines, unable to compete with a shoveled army of poor Congolese, went bust and quit altogether.

In 2007, Rwanda and the Democratic Republic of Congo had the world’s largest and second-largest share of tantalum mines. On January 9, 2007, Apple’s Steve Jobs launched the first iPhone. In 2014, most of the world’s tantalum mines were exported by Rwanda and DRC, including 600 tons from Rwanda and 200 tons from DRC, accounting for more than 70% of the world’s tantalum output.

In 2010, the U.S. implemented the Dodd-Frank Wall Street reform and consumer protection act, which requires U.S. companies that purchase tantalum products and other materials to investigate their supply chains and determine that the materials are not sourced from conflict zones in the democratic republic of Congo. The United States describes minerals from the eastern DRC region that have been repeatedly contested by rebels and government forces as conflict minerals.

Rwanda, Tanzania, and Bolivia are investing in the construction of tantalum and niobium smelting plants due to the implementation of the Dodd-Frank Act in the US and the Conflict Minerals Regulation in the EU. It is expected that the supply of tantalum raw materials in the world, especially in Africa, will become more and tighter in the future.

Stanford Advanced Materials (SAM) is a trusted supplier of high-quality capacitor grade tantalum powdercapacitor grade tantalum wire, and a wide variety of tantalum products. Please visit https://www.samaterials.com/ for more information.

Tantalum VS Niobium

Tantalum and niobium belong to one family in the periodic table. Due to their similar physical and chemical properties, as well as growing together in the same ore body, they are known as the twin of metals.

ta vs nb

Tantalum and niobium were discovered in 1801 and 1802 by Charles Hatchett, a British chemist, and Ekberg, a Swedish chemist. Tantalum niobium ore is the main ore of tantalum and niobium, and a small amount of tantalum and niobium exist in tungsten and some rare earth ores.

Properties

Tantalum and niobium are both high-melting metals with melting points of 2996℃ and 2468℃ respectively. Tantalum and niobium have very stable chemical properties, not only insoluble in nitric acid, and hydrochloric acid, but also insoluble in aqua regia. Tantalum is malleable and can be pulled into strands thinner than human hair or rolled into foil thinner than paper. Tantalum and niobium are both excellent superconducting materials with characteristics of compression and wear resistance.

Applications

Tantalum and niobium are widely used in various fields because of their excellent properties mentioned above.

1. Capacitor

Tantalum can form a compact and stable amorphous oxide film with high dielectric strength, so it is easy to control the anodic oxidation process of the capacitor accurately and conveniently. Tantalum powder sintered blocks can obtain a large surface area in a small volume, so tantalum capacitors are the most excellent capacitors with small volume, large capacity, low leakage current, long service life, and excellent comprehensive performance. Under normal conditions, tantalum capacitors are smaller in size, higher in capacity, and more stable in function than ceramic capacitors, aluminum capacitors, and thin-film capacitors.

Tantalum capacitors have excellent characteristics that cannot be compared with many other capacitors. In the field of microelectronics science and surface mount technology, there is almost no other equivalent capacitor to compete with them. Therefore, 60~ 65% of tantalum is used in the manufacture of tantalum capacitors in the form of capacitor grade tantalum powder and tantalum wire.

Compared with tantalum, the main disadvantages of niobium capacitors are large leakage current (generally 5-10 times of tantalum), low breakdown voltage (< 10V), and low operating temperature (< 105℃), which are not suitable for capacitors with high-reliability requirements and high rated voltage. However, in the range of low voltage (< 10V) and large capacity (> 100muf), niobium capacitors may partially replace tantalum capacitors of the same level.

2. Metallurgical industry

In the metallurgical industry, niobium is mainly used to manufacture high-temperature resistant alloy steel and improve the strength of steel. In the smelting of carbon steel, the strength of the steel can be increased by more than one-third by adding only a few parts per million of niobium. Superalloys made of niobium, tantalum, tungsten, aluminum, nickel, cobalt, vanadium, and other metals are good structural materials for supersonic jet aircraft, rockets, and missiles.

3. Mechanical industry

In the mechanical industry, the cutting tool made of carbides such as niobium carbide and tantalum carbide can withstand a high temperature of nearly 3000℃, and its hardness can be comparable with that of the diamond, the hardest substance in the world.

4. Biomedical industry

Tantalum is an ideal bio-adaptive material in medicine. When it comes in direct contact with human bones, muscle tissues, and fluids, it can adapt to biological cells and has an excellent affinity with almost no human stimulation and side effects. Tantalum can not only be used to make bone plates, screws and clamping rods for fracture treatment, but also can be directly used to repair bones with tantalum plates and pieces and replace broken bones due to trauma with tantalum strips. Tantalum wire and foil can be used to suture nerves, muscles and blood vessels above 1.5 mm, while the extremely thin tantalum wire can replace tendons and even nerve fibers.

Stanford Advanced Materials supplies high-quality tantalum and niobium products to meet our customers’ R&D and production needs. Please visit http://www.samaterials.com for more information.

How is the Tantalum Made?

Tantalum is a sensible choice whenever high corrosion resistance is required. This platinum-gray-colored metal has a density of 16.6 g/cm3 which is twice as dense as steel. With its combination of specific physical and chemical properties, tantalum is an important product in many applications. Do you know how tantalum is made?

tantalum

Tantalum smelting process

Tantalum niobium ore is the main raw material for the production of tantalum, but it is often associated with a variety of metals, so the main step is the decomposition of tantalum smelting concentrates, purification, and separation of tantalum and niobium, producing the pure compound of tantalum and niobium, finally, we can produce metal.

To achieve ore–decomposition, we can use the hydrofluoric acid decomposition method, sodium hydroxide melting method, and chlorination. The method can be used in the separation of tantalum and niobium by solvent extraction, fractional crystallization, and ion exchange method.

Preparation of tantalum

The preparation of tantalum is the process of reducing pure tantalum compounds to metal tantalum. The raw materials are five tantalum oxide, tantalum chloride, five tantalum fluoride, and fluoride (such as K2TaF7,). The reducing agent is sodium, magnesium, other active metals, and carbon and hydrogen. The melting point of tantalum is as high as 3669K, so it is a powder or spongy metal after reduction. It is necessary to further smelting or refining, in order to get dense metal.

The tantalum preparation methods are sodium thermal reduction, carbon thermal reduction, and molten salt electrolysis. Sodium thermal reduction of potassium tantalate is the most widely used method of tantalum production in the world.

The tantalum powder has a complex shape and a large specific surface area. Carbon thermal reduction of five oxidation of tantalum has been an industrial method for the production of tantalum, but because the purity of the product is not high enough, is not as widely used as the sodium reduction method. The molten salt electrolysis method is divided into two ways: electrolyte electrolysis and oxygen-free electrolyte electrolysis. Molten salt electrolysis can only produce metallurgical grade tantalum powder. Five hydrogen fluoride reduction is considered to be one of the most promising methods for tantalum production, but it has not been used in industrial production because of the high requirements of equipment material and environmental protection.

The majority of tantalum powder is directly used for tantalum capacitors in the electronic manufacturing industry, so the tantalum milling process, such as the preparation of tantalum metal is also from tantalum and tantalum powder by vacuum heat treatment, capacitor grade tantalum powder hydrogenation method category.

Sodium thermal reduction process

Sodium metal thermal reduction method is an important method for the production of tantalum powder, is the main method of industrial production of tantalum powder (including metallurgical Ta powder), the metal tantalum powder particle shape is complex, large surface area, suitable for anode material for tantalum electrolytic capacitors, by electron beam melting, vacuum arc melting of tantalum or tantalum sintered in vacuum refining, made of high purity tantalum ingot or rod, and then processed into a variety of tantalum.

In order to obtain high purity tantalum powder, in addition to the main raw material, sodium and potassium fluorotantalate diluent (or NaCl+KCI), sodium chloride (argon or helium) must reach the required purity, must also be dehydration treated strictly at different temperatures in advance. It is also necessary to carry out the vacuum heat treatment at the temperature of 598 ~ 648K. After vacuum heat treatment, potassium fluorotantalate can remove the residual organic matter and hydrogen fluoride, and become the potassium fluorotantalate grain refinement, obtaining fine tantalum powder in reduction.

Since the 1970s, it has been widely used to increase the specific capacitance of tantalum powder. The commonly used doping agent is phosphate, which can be mixed before or after the crystallization of potassium fluoride and can be added before the vacuum heat treatment of tantalum powder. The doping can prevent the sintering of tantalum powder during the sintering of the tantalum anode block, thus avoiding the reduction of the specific surface area of the tantalum anode block. We can remove oxides from metal sodium with the metal-ceramic filter or cold trap method.

The process of reduction of potassium and sodium fluoride in an inert atmosphere at 1153 ~ 1173K temperature and the reduction products are metal tantalum powder, potassium fluoride, sodium fluoride, and diluent which are not involved in the reaction.

Before the 1950s, the solid metal sodium and potassium fluorotantalate layer was placed in the reactor of bomb explosion reduction reaction, although the product of tantalum powder is fine particle size, large surface area, oxygen, and carbon content is high, no practical value.

In this way, the reaction period is too long, the product size is coarse, and can only be used as 3000/uF.V/g low volume tantalum powder. After improvement by liquid-solid mixed loading reaction of sodium-based reduction, the production cycle is shortened 3/4 than gas-liquid reaction, tantalum powder volume increased by more than 30%, but still not ideal will be phased out.

With tantalum capacitors being small and micro, the corresponding need to adopt more surface area tantalum powder, mainly used in the liquid reduction, mainly supplemented by mixing sodium, doping technology, the volume rate of tantalum powder increased to 1000uF-V yield every year.

The fluoride was removed by dipping, and then washed with HCl18% and HF1% solution at 1 2H for 363K, then washed with pure water and dried at 353K temperature. For the preparation of capacitor grade tantalum powder, tantalum powder should be the original size distribution, vacuum heat treatment (see tantalum powder vacuum heat treatment), crushing and screening and modulation post-processing, if necessary, will also increase the magnesium reduction deoxygenation, pickling, washing and plastic processing, in order to obtain high quality and low and high specific capacitance of capacitor grade tantalum powder.

It is expected that the continuous improvement and development of tantalum powder produced by sodium reduction is the result of the miniaturization, miniaturization, and cost reduction of electronic products. Since the 1960s, the specific capacitance of tantalum powder has been increasing, and the capacitance ratio of tantalum powder has reached 22000~26000uF•V/g in the United States, Japan, Germany, and other countries.

Please visit http://www.samaterials.com for more information.

Factors Affecting the Quality of Capacitor Grade Tantalum Powder

The powdered tantalum is dark gray or silver-gray, which is an important raw material for the preparation of capacitors and tantalum materials.

tantalum powder

The quality of capacitor grade tantalum powder used for manufacturing tantalum capacitor cores is mainly measured by its physical properties, chemical composition, and electrical properties.

Physical Properties

Physical properties mainly include average particle size, particle shape, fluidity and forming density. Low-pressure series products should have a small average particle size, complex grain shape, and low forming density, while high-pressure series products should have a large average particle size, simple grain shape, and high forming density. The fluidity determines whether tantalum powder can be formed by an automatic forming machine. Therefore, with the rapid increase in the production of small chip tantalum capacitors, great attention has been paid to the fluidity of tantalum powder.

Chemical Composition

The chemical composition has a direct effect on the electrical properties of tantalum powder. High impurity content, especially high content of phosphorus, boron, oxygen, carbon, potassium, sodium, and iron, will increase the leakage current and decrease the breakdown voltage of tantalum anodized film, so as to degrade the electrical properties of tantalum powder. However, the content of certain elements in tantalum powder is not as low as possible. It is found that adding certain selected elements can improve certain electrical properties of tantalum powder, and it has been proved that adding a small amount of phosphide to tantalum powder can inhibit the shrinkage of tantalum during sintering and thus increase the capacitance of tantalum powder by weight, while the breakdown voltage of tantalum powder can be increased by adding trace aluminum compounds with high dielectric strength.

Electrical properties

Electrical properties refer to the dc leakage current, breakdown voltage, and capacitance of the oxide film on the surface of tantalum anode after weighing, pressing, vacuum sintering, and anodizing of tantalum powder. All these properties are not only determined by the intrinsic characteristics of amorphous tantalum pentoxide anodized film but are also closely related to the physical properties and chemical composition of tantalum powder.

Please visit http://www.samaterials.com for more information.