Effects of Grain-Boundary Sliding and Plastic Deformation of Grains on the Formation of Grain-Boundary Cracks in a Double Cylindrical Bicrystal of a Cu-SiO_2 Alloy

摘要

A double cylindrical bicrystal is a bicrystal consisting of a cylindrical inside grain with a second grain wrapped around its curved side surface. Using a double cylindrical bicrystal of a Cu-SiO_2 alloy, tensile tests were performed at 800 K under 2 x 10~(-4) s~(-1). Three specimens cut from the same bicrystal were deformed to three different strains. Preferential formation of grain-boundary cracks around the cylindrical inside grain was observed after the tensile tests. In addition to the occurrence of grain-boundary sliding, the misfit of slip deformation at the grain boundary affects the formation of the grain-boundary cracks.