HARDENING STAGES OF [112] COPPER SINGLE-CRYSTALS AT INTERMEDIATE AND HIGH-TEMPERATURES .2. SLIP SYSTEMS AND MICROSTRUCTURES

This part II reports the main features of the slip systems and the mic rostructures which are characteristic of each stage in the three tempe rature regimes. It is shown that in regime 1, a misoriented cell struc ture develops through {111} glide. In stage II, walls are approximatel y parallel to the two primary active {111} planes. In stage III the {1 11} cross-slip plane is activated with walls parallel to it. In stage IV glide polygonization walls are observed which are perpendicular to the above {111} slip planes. In temperature regime 2, a misoriented su bgrain structure takes place. In stage IV, abundant non compact slip i s observed along the two symmetrical primary slip directions. This mec hanism is thought to be controlling the thermal activation of tau(IV). The subboundaries are oriented almost parallel to the active slip pla nes or perpendicular to them. The macroscopic observations of part I o f this study are confirmed by the changes in microstructure and slip s ystems as a function of the hardening stages and the temperature regim es.