US development of new tungsten alloy penetrator, will replace the depleted uranium alloy

 

University of Massachusetts (MIT) researchers have developed a new type of tungsten powder metallurgy ferrochrome alloy W-7Cr-9Fe, can replace the depleted uranium penetrators alloys. Test results show that, W-7Cr-9Fe alloy nano-indentation hardness up to 21 GPa, which is about twice the nanocrystalline iron-based alloy or coarse-grained tungsten, much higher than the current commercial tungsten alloys.

 

During the preparation of this alloy are: first nano crystalline powder, then made into a desired shape. Among them, the use of high-energy ball milling the powder is prepared by powder metallurgy process, including the repeated shear prompted alloy powder mix, accompanied by heat-activated recovery process, the alloy to return to equilibrium.

 

The molding process using an electric field assisted sintering hot pressing process, the researchers noted that when the processing time of 1 minute, the temperature is 1200 ℃, the alloy crystal structure obtained is good, and the maximum hardness. The long processing time and high temperature leads to the metal grain coarsening, strength is lowered. Micrographs show, W-7Cr-9Fe alloy grain structure prepared by MIT researchers can reach 130 nm.