With efforts underway to ban lead-based ammunition as a potential health and environmental hazard, scientists are reporting new evidence that a prime alternative material for bullets -- tungsten alloys-- may not be a good substitute The report, which found that tungsten alloys accumulate in major structures of the immune system in animals, appears in ACS' journal Chemical Research in Toxicology.

Jose Centeno and colleagues explain that tungsten alloys have been introduced as a replacement for lead in bullets and other munitions. It resulted from concern that lead from spent ammunition could harm wildlife when it dissolves into water in the soil, streams, and lakes. Scientists thought that tungsten alloys were relatively non-toxic, and a "green" replacement for lead. Recent studies suggested otherwise, and with small amounts of tungsten alloys also used in some artificial hips and knees, Centeno's group decided to gather further information on tungsten alloys.

They added small amounts of  tungsten compound to the drinking water of laboratory mice, used as surrogates for people in such research, and examined the organs and tissues to see exactly where tungsten ended up. The highest concentrations of tungsten were in the spleen, one of the main components of the immune system, and the bones, the center or "marrow" of which is the initial source of all the cells of the immune system. Further research, they say, will be needed to determine what effects, if any, tungsten may have on functioning of the immune system.


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Tungsten alloy in high temperature tooling is called as tungsten alloy extrusion dies and die casting components.

Tungsten alloy can save time and money in hot metal working. The high tungsten content offers good resistance to thermal cracking, erosion, soldering and the effects of heat cycling in hot metal working processes. Experience has shown that, due to its non-wetting properties, tungsten alloy has significantly increased longevity over the equivalent parts in steel or cast iron. Tungsten alloy does not require heat treatment before use.

Tungsten alloy can save time and money in the extrusion of copper and copper alloys because its high tungsten content offers good resistance to metal pick up, erosion, soldering and the effects of heat cycling such as thermal cracking. This significantly increases the operating life of die inserts compared to the same components made from steel or stellite.


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Tungsten heavy alloy, also called tungsten heavy density alloy. Its main component is tungsten which consist of 85-98%. Therefor the first step of manufacturing heavy alloy is to mix the metal powder, and then trough pressing and liquid-phase sintering processes.

Tungsten heavy alloy is excellent in high density, high strength, good electric and heat conduction.Tungsten heavy alloy has the advantages of good corrosion resistance and antioxidant activity. Besides,
Tungsten heavy alloy has good capability in absorbing rays.

Tungsten heavy alloy is used in nuclear shielding, vial shield, isotope container, high- temperature die, electrical rivet, tungsten sinker bar, shrapnel head, golf and tungsten alloy dart parts spheres. It is core for armourpiercing bullet measurement.


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In recent years, there has been an increased desire to replace depleted uranium (DU) anti-armor penetrators with tungsten heavy alloy (WHA) penetrators. However, the ballistic performance of WHA does not compare with that of DU.

Many methods of improving the ballistic properties of tungsten heavy alloys have been explored. One recent method includes jacketing a long thin core of WHA with a more ductile metal. However, applying thermal-sprayed coatings onto a tungsten substrate is a challenge. The differences in the coefficients of thermal expansion (CTE) make it difficult to achieve adequate adhesion of most coatings to tungsten. Further compounding the problem are residual stresses inherent in thermally sprayed coatings. The thicker the coating desired, the more likely disbonding will occur upon cooling of the substrate. Early attempts to apply an Ni coating (0.0lOA).020 in thick) to a tungsten substrate yielded immediate disbonding and/or cracking of the coatings. The work presented is an investigation focusing on modifications to spray parameters and the use of multiple thin layers to minimize heat transfer and achieve better adhesion.

The use of a material with a CTE nearer to that of tungsten heavy alloys as a bond coat and grading of coating materials was also examined as a method for increasing the overall adhesion of the coating system.


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