Cu-Ni-Si合金の組織と機械的性質に及ぼす微量添加元素の影響

摘要

The microstructure and mechanical properties of Cu-2.0 mass percent Ni-0.5 mass percent Si alloys with and without 0.1 mass percent Sn, Ag and Mg have been investigated. The Mg addition increases most the formation rate of disk-shaped delta -Ni_2Si particles. The Mg addition produces the largest increase in strength and the highest resistance to stress relaxation. The improvement of strength or stress relaxation resistance is caused by the decrease in interparticle spacing by the Mg addition or by the Mg-atom-drag effect on dislocation motion. The stress relaxation resistance for the Cu-Ni-Si alloy with a large grain size of 150 mu m is higher than that for the alloy with a small grain size of 10 mu m because the density of mobile dislocations in the former alloy is lower.