Studies on Copper Alloys Containing Chromium (4th Report). On the Effects of Silicon and Iron Upon the Properties of Copper Alloys Containing Chromium

Abstract

Samples of Cu-0.54%Cr alloys containing silicon and iron up to 0.12% respectively were prepared by vacuum melting and casting. With these samples the author studied the effects of silicon and iron additions upon the softening,the age-hardening and the high temperature strength. Silicon and iron contents slightly raised increased softening temperature and high temperature strength. According to M. G. Corson, the precipitation in Cu-Cr alloys containing silicon was much easier to control than in Cu-Cr alloys, but the author found that the aging rate and the maximum tensile strength decreases and the precipitation became less easier to control with rise in silicon content. Therefore the author thinks that a silicon content of above 0.08% is highly objectionable in Cu-0.54%Cr alloy. On the otherhand, addition of iron had little effect upon the aging of Cu-Cr alloys. The activation energy of precipitation of these alloys were all constant and its value was 65,300 cal/mol.