抄録
Tensile tests and fatigue tests were conducted with a α-brass ultra-fine grains (UFG) from 1 to 5μm diameter produced either by severe plastic deformation through equal angular pressing (ECAP) or multiple rolling, where the minimum grain size obtained by ECAP was 4.9 μm, and 1.0 μm by the multiple rolling. The proof stress, tensile strength and fatigue limit were increased with decreasing grain size, and Hall-Petch relationships were established. The relationship, however, depended on the thickness of specimen, i.e., those were lower for thin plate. The proof stress increased by ten-fold by the grain refinement, while the tensile strength increased by two-fold. The fatigue strength also increased; however, the effect was not as much as the static strengths.
