Dynamic fracture of tungsten heavy alloys

摘要

Dynamic fracture of tungsten heavy alloys was induced by two different test techniques. The first was spall (e.g., 1-D strain fracture). The second was transverse impact, as occurs in a yawed penetrator. Spall failure is stress driven, and spall stress corresponds to the threshold for void formation, which is 2.6GPa for a 91% WNiCo alloy and 2.1-2.5GPa for a 95% WNiFe alloy. Yaw-induced fracture, on the other hand, is strain driven. Surface flaws can provide fracture sites. At the meso scale, grain cleavage is mainly responsible for transverse fracture. Grain fracture also appears to play a critical role in the initiation of spall fracture.