Effect of ECAP by Route BC and Aging Heat Treatment on the Structure and Properties of Cu0.4Cr0.3Zr Alloy

Cu0.4Cr0.3Zr alloy was extruded by equal-channel angular pressing (ECAP)-BC path at room temperature and aged at 450 degrees C for 1 h. Scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) were used to detect the microstructure, mechanical properties and electrical conductivity of the materials during deformation and aging. The effect of cyclic loading alternating shear stress on the microstructure transformation and properties of the materials was analyzed, and the dynamic mechanism of the formation and evolution of micro/nano precipitates in the process was explored. The results show that the cellular structure formed in the matrix at the early stage of deformation can be rapidly transformed into micro/nano structure by ECAP alternating shear and aging treatment. Supersaturated Cr and Zr are dispersed in the crystal, and Cr, Zr and CuxZr intermetallic compounds are precipitated discontinuously at the grain boundary. The alloy strength reached 538.6 MPa and the conductivity was 74.9% IACS. The improvement of tensile strength and microhardness of the alloy is attributed to the interaction of grain refinement, dislocation strengthening and precipitation strengthening during plastic deformation and aging treatment. The high conductivity is mainly attributed to the precipitation of nano-Cr during the subsequent aging treatment.