The Effect of Severe Plastic Deformation and Heat Treatment on CuCrZr Alloys

Abstract

CuCrZr alloy was subjected to equal channel angular pressing method, belonging to the severe plastic deformation group, followed by heat treatment under different ageing conditions to optimize mechanical properties of the alloy. Before equal channel angular pressing, CuCrZr alloy was treated by solution annealing at temperature 1020 • C for 1 h. Afterwards, samples were pressed through an equal channel angular pressing die once at room temperature and subjected to artificial ageing under different conditions (200, 400, 450, 480 • C for 30, 60, 90, 120, 150 min). Optimization of the CuCrZr alloy was done through the study of mechanical properties and microhardness as a function of ageing temperature and time considering the progress in microstructural/substructural features.

Additive manufacturing of CuCr1Zr by development of a gas atomization and laser powder bed fusion routine

“…The TEM image of Fig. 12b reveals the occurrence of nano-sized precipitates, probably being rich in Cr, which were also reported in [32] that have a strengthening effect in CuCr1Zr. Thus, the formation of probably Cr rich precipitates on the nano-scale and ZrO 2 an the microscale after ageing lead to a significant increase in hardness, exceeding the values of the cast benchmark samples and values reported in, e.g., [2,32].…”

“…For non LPBFbuilt samples, the formation of ZrO 2 as a strengthening phase is neither reported for non-aged nor for aged samples. However, they tend to have a strengthening effect in LPBF-built CuCr1Zr by their fine dispersion, leading to a significantly higher hardness as compared to the benchmark sample and to literature values (for example to [2,3,32]). The TEM image of Fig.…”

“…By application of heat treatments, a precipitation hardening of Cu alloys may be achieved. In the case of CuCr1Zr, the formation of Cr, Cu 4 Zr, and Cr 2 Zr precipitates lead to an increase (i) in hardness and (ii) of the electric conductivity [2][3][4][5]32]. Ageing was performed at 480 • C for 4 h.…”

The Influence of Severe Plastic Deformation and Subsequent Annealing on the Microstructure and Hardness of a Cu–Cr–Zr Alloy

“…In ECAP, the shear strain is accumulated in the billet during repetitive pressing, which enhances the microstrain with a simultaneous reduction in the size of the grains to a nanocrystalline range [8]. SPD processing was successfully applied to different alloys, such as Cu-Cr-Zr alloys [9,10].…”