Views: 10 Author: China News Publish Time: 2015-05-20 Origin: China News
According to the China Defense Science and Technology Information Network reported that the US is expected to develop a new tungsten-chrome-ferro(WcrFe) alloy for armor-piercing to replace the depleted uranium alloys.
MIT researchers developed a new PM alloy WCr7Fe9 wich can replace the depleted uranium alloys in armor piercing bullets. The test results show that indentation hardness of the new tungsten alloy WCr7Fe9 is 21Gpa, which is much higher than nowadays’ tungsten alloys for business usages and is about twice than the data of nanocrystalline iron-based alloy or coarse-grained tungsten.
The preparation of this alloy are: first preparing nanocrystalline powder, then made into a desired shape. Among them, the powder is a powder metallurgy process using high-energy ball milling, including repeated shearing prompted alloy powder is mixed, accompanied by heat-activated recovery process to restore the balance of the alloy
The molding process using field-assisted sintering hot pressing process, the researchers noted that when the processing time is 1 minute at a temperature of 1200 ℃, the alloy crystal structure will be perfect and get the maximum hardness. The over long processing time and too high temperature will cause metal grain coarsening and lower the intensity. Photomicrographs shows that the W-7Cr-9Fe alloy grain structure prepared by MIT researchers can reach 130 nm.