Latent hardening in copper and aluminium single crystals

Abstract

Latent hardening tests are performed in tension on copper and aluminium single crystals. The latent hardening ratios (LHRs) are measured for different values of primary shear strain in Stage 1, and for various latent systems. These LHRs have an increasing variation in the earlier stage of primary slip before decreasing towards values higher than unity. Latent systems are classified into three groups, according to their LHR intensity, for both copper and aluminium, but the LHRs are higher in copper than in aluminium. These experimental results are discussed in terms of short range interactions between primary and latent dislocations. If the anisotropy of dislocation densities is taken into account, one obtains a synthetical description of latent hardening behaviour which is in agreement with all the reported experimental results.