Microstructures and strengthening mechanism of <scp>2D</scp> laminated structures in Ni balls after high‐speed collisions with <scp>316 L</scp> stainless steel

In many cases, due to high surface stress, stress concentration and wear, the metal material starts fail from surface. It is necessary investigate interface evolution characteristics under high-speed collisions for widely used materials. The microstructures strengthening mechanism of Ni balls after with 316 L stainless steel were investigated by a self-designed test system. was found that ultrafine twins α'-martensite formed in (316 SS) near region. elongated nano/ultrafine lamellar structures high-angle grain boundaries ball central region, while more equiaxed grains random orientations edge region friction process shear stress. gradient structure normal strain could promote formation finer Moreover, addition refinement strengthening, sufficient intragranular recrystallization facilitated activation dislocations increased