Influence of prefabricated microcracks on dynamic deformation behavior and shear fracture of tungsten alloy
In this paper,the static and dynamic mechanical behaviors of 91W-6.3Ni-2.7Fe (91W) alloy with prefabricated microcracks caused by hot rotary forging were studied.The results show that,there is no significant deformation of tungsten particles after rotational forging deformation,and about 10％ of tungsten particles have prefabricated microcracks.The tensile yield strength of the alloy is 1.3 GPa and the elongation is 6.5％.The compressive yield strength is 1.4 GPa,the compressive plasticity is 45％.Under high speed impact conditions,the alloy strength is about 2 GPa,and a significant adiabatic shear band is formed at strain rate of 3000 s-1.It is found that the prefabricated microcracks in the alloy promote the crack propagation in the adiabatic shear band,which makes the alloy produce adiabatic shear failure under small strain,thus improving the self-sharpening of the alloy.In addition,the JC constitutive model of 91W alloy with prefabricated microcracks is established,which can accurately predict the stress state of 91W alloy under high-speed impact.
tungsten alloyadiabatic shearmicrostructuremechanical propertiesconstitutive model
万方数据
维普
