Shock compression of single-crystal stainless steel

We studied the orientation-dependent dynamic properties and plastic deformation mechanisms in single-crystal austenitic FeCr18Ni12.5 stainless steel shocked to peak stresses ranging 3.8-12.0 GPa. The 〈110〉 and 〈111〉 principal Hugoniots generally match that of polycrystalline 304L stainless steel, but the 〈100〉 Hugoniot exhibits lower shock velocities and comprises two distinct regions. The Hugoniot elastic limits (HELs) and spallation strengths range 0.5-1.2 GPa and 2.2-3.8 GPa, respectively, and exhibit trends previously observed in polycrystalline steels. We generally observed the largest HELs along 〈100〉 and the largest spallation strengths along 〈111〉. Microscopy revealed larger twin and martensite fractions in the 〈100〉 samples, correlations in twinning and martensite prevalence with dynamic response, and orientation-dependent differences in dislocation behavior near the spallation plane.