SOLID SOLUTION HARDENING OF METAL CRYSTALS

The dependence of the yield stress of binary solid solution crystals on temperature and alloy concentration is explained in terms of a simple model in which the breakaway of dislocations from short rows of pinning points is rate determining. With an assumed binding energy of about 0·01 ev between dislocations and zinc atoms the calculated yield stress of α-brass single crystals agrees quantitatively with measured values in the range 0-400°K. The yield stress of dilute solid solutions, particularly iron alloys, and a possible bearing of the present theory on the problem of the temperature dependence of the Peierls stress, are discussed briefly.