Impact and Dynamic Deformation Behavior of Mechanically Alloyed Tungsten Heavy Alloy

Abstract

93W-5.6Ni-1.4Fe tungsten heavy alloy was fabricated by mechanical alloying process using elemental poweders of tungsten, nickel and iron, followed by sintering at temperatur of 1445-1485c under hydrogen atmosphere. the tungsten heavy alloy sintered using mechanically alloyed powders showed finer tungsten particles about 5-18um with high density above 99% at shorter sintering time than that fabricated by cinventional liquid-phase sintering process. charpy impact energy of mechanically alloyed tungsten heavy alloy increased woth increasing the matrix volume fraction and with decreasing the W/W CONTIGUITY. the high strain rate dynamic deformation behavior of tungsten heavy alloy using torsional Kolsky bar test exhibited different fracture modes dependant on microstructure. while the brittle intergranular fracture mode was dominant when the tungsten particles were contiguously interconnected in tungsten heavy alloys solid-state sintered below 1460c, the ductile shear fracture mode was dominant when the tungsten particles were surrounded by ductile matrix phase in tungsten heavy alloys liquid-phase sintered above 1469c.