A new powder metallurgy technology is developed in the United States.

According to the China national defense science and technology information network reported that the United States to develop a new type of tungsten alloy penetrators is expected to replace the chromium depleted uranium alloy.

Massachusetts Institute of science and Technology (MIT) developed by researchers a new tungsten chromium powdermetallurgy alloy W-7Cr-9Fe can replace wear armor of depleted uranium alloys. Test results show that W-7Cr-9Fe alloy nano indentation hardness up to 21 Japa, is approximately two times as that of nanocrystalline Fe based alloy or coarse grained tungsten, far higher than the current commercial tungsten alloy.

The preparation process of the alloy is: firstly, preparing the nanometer crystal powder, and then making the required shape. The powder is prepared by high-energy ball milling powder metallurgy process, including repeated shearing to make the alloy powder mixed, and accompanied by the thermal activation recovery process, so that the alloy can be recovered to the equilibrium state.

The molding process using the electric field assisted sintering hot pressing process, the researchers pointed out that when the processing time is 1 minutes, the temperature is 1200 degrees Celsius, the alloy crystal structure is good, and the highest hardness. The excessively long processing time and high temperature can cause the metal to become thicker and the strength decrease. The micrographs showed that the grain structure of W-7Cr-9Fe alloy prepared by MIT can reach 130 nm.