Square L12 precipitates inducing high susceptibility to adiabatic shear in 3D printed fine-grained tungsten heavy alloy with high-entropy alloy matrix

Tungsten heavy alloys with a L12 precipitation-hardening high-entropy alloy matrix exhibit high susceptibility to adiabatic shear, but the relationship between the size and morphology of L12 precipitates and the adiabatic shear behavior is not well understood. This work systematically studies the effect of different size and morphology L12 precipitates on the mechanical properties and susceptibility to adiabatic shear of the tungsten heavy alloy with an AlCrFeNiV-system high-entropy alloy matrix (W-HEA). The results show that the W-HEA with square L12 precipitates has tensile strength of 1300 MPa and dynamic compression strength of 2100 MPa at a stain rate of 6000 s−1. The higher interfacial energy of square L12 precipitates leads to the faster re-dissolution of square L12 precipitates into the matrix than ultrafine and lath-like L12 precipitates under temperature rise during shearing, which can sharply soften the shearing location and contribute to the narrowest adiabatic shear band (ASB) with width of 15 μm.