Investigation on the penetration performance and "self-sharpening" behavior of the 80W-14Cu-6Zn penetrators

In order to investigate the penetration performance of the 80W-14Cu-6Zn alloy prepared by the pressureless infiltration method, ballistic impact experiments were conducted, and the 90W-7Ni-3Fe alloy and 35CrMnSiA alloy were tested for comparison. The 80W-14Cu-6Zn penetrator exhibits the best penetration performance with the penetration depth of 30.35 mm which increases by 29.9% and 99.0% respectively compared with the penetrators made of 90W-7Ni-3Fe alloy and 35CrMnSiA alloy. The remnant of the 80W-14Cu-6Zn penetrator maintains an acute head indicating an excellent "self-sharpening" capacity. On contrast, both the remnants of the 90W-7Ni-3Fe and 35CrMnSiA penetrators show mushroom-like heads. Microstructure analysis indicates that high strength and proper critical failure strain are responsible for the "self-sharpening" effect of the 80W-14Cu-6Zn penetrator. While the 80W-14Cu-6Zn alloy penetrator is subjected to ballistic impact, plastic deformation occurs to the head of the penetrator mainly and deformation layer is formed on the surface of the penetrator. When the plastic strain of the deformed layer reaches the limit of the critical failure strain, the deformed parts will fall off in timely fashion leading to the formation of the acute head. Besides, due to severe impact between the penetrator and the target plates, Cu-Zn matrix has been squeezed out and formed thin Cu-Zn alloy film coating on the wall of the shot hole, which can act as the lubricant and reduce the friction between the penetrator and the target plates. Both the "self-sharpening" capacity and "self-lubricating" effect of the 80W-14Cu-6Zn alloy eventually optimize the penetration performance.