固溶体Cu-Ge合金の低温焼鈍について

Abstract

In a previous paper, the authors have expected from electrical resistivity changes of the deformed or quenched Cu-Ge alloys that anneal-hardening might not occur in Cu-Ge solid solutions.In this paper, (i) it was ascertained that the anneal-hardening did not occur in the Cu-Ge alloys, but it occurred in Cu-Al alloys. (ii) In order to make clear the origin of anneal-hardening, the flow-stress and the resistivity change by plastic deformation at room temperature are measured for Cu-Ge, Cu-Al and Cu-Ni alloys, and the X-ray (111) and (200) peak shifts by low temperature annealing were investigated in addition to Vickers hardeness measurment. (iii) The cause of anneal-hardening introducing wipe-out number was discussed. The results obtained are as follows:(1) The anneal-hardening does not occur in Cu-Ge and Cu-20.77 at%Ni solid solutions, but it is observed in a Cu-10.37 at%Al alloy.(2) The specific resistivity change Δρ⁄ρ0 by cold work and the work hardening of Cu-Al alloys are larger than those of Cu-Ge alloys.(3) The isothermal annealing curve of the X-ray (111) and (200) peak shift difference of Cu-10.37 at%Al alloy has two steps corresponding to the isothermal anneal hardening.(4) The smaller the wipe-out number of solute atom, the easier solute atoms may form a kind of fine ordered lattice structure. The anneal-hardening may be attributed to the formation of the ordered lattice structure rather than the segregation of solute atoms at the stacking faults.