OS1105 すべり摩擦を受けた銅双結晶における粒界形成

Abstract

Sliding wear tests were conducted on copper bicrystals having a boundary plane perpendicular to worn surface. Three kinds of the bicrystal specimens were prepared. Two of these bicrystals had orientation relationship of Σ3, but differed in slip plane geometries relative to surface. The other bicrystal had an incompatible boundary. Constituent grains of all the specimens had {111} or {110} surface. The bicrystal specimens were subjected to sliding wear, which results in circle-like wear track on the surfaces. In order to investigate microstructure below the worn surfaces, the specimens were cut along the wear track and then cross sections were analyzed by electron backscatter diffraction (EBSD) technique. For all the bicrystal specimens, low-angle grain boundaries were detected below subsurface region where equi-axed fine grains were generated. In the Σ3 bicrystal specimen having {111} surface, the low-angle boundaries were inclined to the worn surface. For the case of {110} surface, the low-angle boundaries were parallel to the worn surface. Even in the close vicinity of the boundaries, no grain-boundary influence on the low-angle boundary formation was recognized in the Σ3 bicrystals. It was found that morphology of the generated low-angle boundaries was certainly affected by the presence of the grain boundary in the incompatible bicrystal.