Micro-yielding in a precipitation hardening Cu 1.81 wt % Be 0.28 wt % Co alloy

Abstract

The microstrain characteristics of a polycrystalline Cu 1.81 wt % Be 0.28 wt % Co precipitation hardening alloy have been determined for various precipitate conditions. The friction stress derived from measurements of closed hysteresis loops was found to remain constant (∼ 3 MN m⁻²) for all the conditions investigated. In contrast, the microscopic yield stress (MYS) remained constant (18 to 24 MN m⁻²) for most ageing conditions, but increased significantly (to 48 to 64 MN m⁻²) for conditions associated with a high G.P. zone or γ′ precipitate density.