A method is proposed for evaluating the strain-hardening exponent (n) and the 0.2% yield stress (σ0.2) for fcc metals solely through the ultra-microhardness technique. To this end, ultra-microhardness (Hum) and Vickers hardness (Hv) measurements together with tensile tests were carried out for Ni and Al with various n and σ0.2. The value of (Hv is proportional to Hum at the load P, and the proportional constant depends on P but scarcely on metals. The ratio of um(P) Hum0(P) is scaled solely by n as a linear function independent of the specific metal, where Hum0(P) is the value of Hum(P) of specimens which show no strain-hardening. Based on the results and Cahoon's relation which relates Hv, σ0.2 and n, the values of n and σ0.2 are evaluated solely through the ultra-microhardness technique. The proposed equation can be explained in terms of a constitutive equation for polycrystalline metals.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Materials Science(all)
- Nuclear Energy and Engineering