tantalum foil – Magic Metal Tantalum

Is Tantalum Worth More Than Gold?

Why is tantalum so valuable?

The most valuable of metal worth materials is not gold or platinum like you might expect, but a metal you’ve possibly never heard of: tantalum.

There’s a good reason for this.

The rarest stable element- Tantalum

As you know, Tantalum is the rarest stable element in our entire solar system, with just one atom of tantalum for every 181 billion atoms of other elements.

Tantalum is a lithophile element with chalcophile affinities. Tantalum is almost exclusively found in complex oxide and hydroxide minerals, with the exception of the borate mineral behierite and the only known non-oxide, tantalum carbide TaC.

Common Ta minerals include tantalite (Fe,Mn)(Ta,Nb)2O6, formanite YTaO4, and mikrolithe. Tantalum is nearly always found in association with Nb. The most common host minerals for Ta in igneous rock types include pyroxene, amphibole, biotite, ilmenite, and sphene.

Excellent characteristics- Tantalum

Tantalum has a series of excellent characteristics such as a high melting point, low vapor pressure, good cold processing performance, high chemical stability, strong resistance to liquid metal and acid and alkali corrosion, and large dielectric constant of the surface oxide film, which makes it an important modern functional material.

Extremely good corrosion resistance – Tantalum

Tantalum rapidly generates a surface oxide film that closely covers its metallic substrate in almost any environment, which is extremely thin and dense, impervious to almost all media, and self-healing once damaged. Thanks to this excellent protective film, tantalum has extremely good corrosion resistance. Except for fluorine, hydrofluoric acid, acidic solutions containing fluorine ions, fuming nitric acid, and strong alkalis, tantalum is impervious to corrosion in most media.

Wide Applications – Tantalum

With its combination of specific physical and chemical properties, tantalum is an important product in many applications:

Tantalum features a high degree of biocompatibility. For this reason, it is used in medical technology as a radiographic contrast agent and in the production of bone replacement material and implants.
• In the aerospace and energy industries, tantalum increases the corrosion resistance of alloys in turbine blades.
• Tantalum’s chemical corrosion and high-temperature resistance properties provide many benefits to the chemical process industry. For this reason, tantalum is used in the production of reactor coatings, heat exchangers, and pipelines
• Its ability to form an extremely thin oxide coating which provides a protection layer, makes tantalum the material of choice in the production of small, high-quality capacitors

In conclusion

We use our “unyielding” material – Tantalum, for example, tantalum foil, and tantalum powder, are used to produce heat exchangers for the equipment construction sector, charge carriers for furnace construction, implants for medical technology, and capacitor components for the electronics industry.

What are the Uses of Tantalum?

The role and uses of tantalum

It can be drawn into thin tantalum foil in the form of a fine tantalum wire. Its coefficient of thermal expansion is very small.

Tantalum has excellent 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 tantalum 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 on its surface.

Chemical properties of tantalum

Tantalum 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.

In 175 degrees in the concentrated sulfuric acid for 1 year, the thickness of the corrosion is 0.0004 mm, tantalum into 200 degrees in the sulfuric acid soaked for a year, the surface layer is only damaged by 0.006 mm. At 250 degrees Celsius, the corrosion rate increases to 0.116 mm per year.

At 300 degrees, the rate of corrosion is accelerated, soaking 1 year, the surface was corroded 1.368 mm. In fuming sulfuric acid corrosion rate is more serious than in concentrated sulfuric acid, soaked in the solution at 130 degrees for 1 year, the surface was corroded by the thickness of 15.6 mm.

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.

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.

Why Do Electrolytic Capacitors Explode?

If you want to know why the electrolytic capacitor explodes, first you have to know what the electrolytic capacitor is. An electrolytic capacitor is a kind of capacitance. The metal foil is the positive electrode (aluminum foil or tantalum foil), and the oxide film (aluminum oxide or tantalum oxide), which is closely attached to the metal, is the dielectric. The cathode consists of conductive material, electrolyte (which can be liquid or solid), and other materials. Because the electrolyte is the main part of the cathode, the electrolytic capacitor is hence named. At the same time, the capacitance of the electrolytic capacitor cannot be connected wrongly.

Tantalum electrolytic capacitor mainly consists of sintering solid, foil winding solid, sintering liquid, and so on. The sintered solids account for more than 95% of the current production and are mainly composed of non-metallic sealed resin.

The aluminum electrolytic capacitor can be divided into four types: the lead type aluminum electrolytic capacitor; Horn type aluminum electrolytic capacitor; Bolted aluminum electrolytic capacitor; Solid aluminum electrolytic capacitor.

The possible reasons for the capacitor explosion are as follows:

The breakdown of the internal components of the capacitor is mainly due to the poor manufacturing process.
The capacitor is damaged by insulation to the shell. The high voltage side of the capacitor is made of a thin steel sheet. If the manufacturing process is poor, the edge is uneven with burr or serious bend. The tip is prone to corona, and the corona causes the breakdown of oil, the expansion of the case and the drop of oil. In addition, when the cover is closed, if the welding time is too long, the internal insulation burns and produces oil and gas, causing the voltage to drop greatly and damage.
Poor sealing and oil leakage. The insulation resistance is reduced due to the poor sealing of the assembly casing. Or the oil spill caused the oil surface to drop, resulting in the extreme shell direction discharge or component breakdown.
The belly and the inside dissociate. Due to the internal corona, breakdown discharge, and serious dissociation, under the action of overvoltage, the starting free voltage of the element is reduced to the working electric field intensity. This causes the physical, chemical and electrical effects to accelerate the aging and decomposition of the insulation, producing gas and forming a vicious circle, the pressure of the case is increased, causing the drum to explode
A capacitor explodes with an electric charge. All capacitors with rated voltages are forbidden to be charged. Each time the capacitor bank recloses, the capacitor must be discharged for 3min after the switch is disconnected. Otherwise, the voltage polarity of the closing moment may be caused by the opposite polarity of the residual charge on the capacitor. For this purpose, a capacitor bank with a capacity of more than 160kvar is generally required, and automatic tripping device should be installed when there is no pressure. And the capacitor bank switches are not allowed to install automatic reclosing.

In addition, it may be caused by high temperature, poor ventilation, high operating voltage, excessive voltage harmonic component or operating overvoltage, etc.

Stanford Advanced Materials (SAM) is a leading supplier and manufacturer of high-quality capacitor grade tantalum powder and tantalum wire with competitive price and great delivery time. Please visit http://www.samaterials.com for more information.

Where Can We Find Tantalum Metal?

Tantalum metal mainly exists in tantalite ore and is symbiotic with niobium. Tantalum is of moderate hardness and ductility and can be drawn into tantalum wire or tantalum foil. Tantalum has a wide range of applications due to its characteristics， and it widely exists in tantalite, tantalum alloy, tantalum powder, tantalum capacitors, etc.

Tantalum alloy is an alloy based on tantalum adding other elements. The tantalum anode oxide film is stable and corrosion-resistant. It has excellent dielectric properties and is suitable for making the electrolytic capacitor. Tantalum is highly resistant to chemical corrosion. Except for hydrogen fluoride, sulfur trioxide, hydrofluoric acid, hot concentrated sulfuric acid and alkali, tantalum can resist the corrosion of all organic and inorganic acids. Therefore, it can be used as corrosion resistant materials for chemical industry and medicine.

As tantalum is similar to some rare elements such as uranium, thorium, rare earth, titanium, zirconium, tungsten, and common elements tin, calcium, iron, and manganese in crystalline chemistry, it is easy to have equivalence and heteromorphism.

The compact oxide film formed on the surface of metallic tantalum has the properties of valve metal of unidirectional conduction. The anodic film made of tantalum powder has chemical stability (especially in acidic electrolyte stability), high resistivity (7.5 x 1010 Ω, cm), dielectric constant (27.6) and small leakage current. Tantalum is not only the raw material for the production of pure metal tantalum but also used in the electronics industry. Lithium tantalate monocrystals and special optical glass with high refraction and low dispersion can be used as a catalyst in the chemical industry.

Tantalum oxide is a white powder insoluble in water and acids, but soluble in molten potassium bisulfate and hydrofluoric acid. The minerals containing tantalum and niobium are mainly iron tantalum and calcined greenstone. The ones containing more tantalum are called tantalite, while the ones containing more niobium are called niobite.

The design of tantalum capacitors requires that the product performance parameters of tantalum capacitors can meet the circuit signal characteristics. However, it is often impossible to guarantee that the above two tasks are done well. Therefore, it is inevitable that failures of one kind or another will occur in the process of use. The solid tantalum capacitors were first developed in 1956 by Bell Laboratories in the United States. Tantalum capacitors can easily obtain large capacity, and there are few competitors in power filter, ac bypass, and other applications.

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

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