Effect of cold rolling and aging treatment on the microstructure and properties of Cu–3Ti–2Mg alloy

The influence of aging treatment on the microstructure evolution and properties of prior cold rolled Cu–3Ti–2Mg alloy was studied. The X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM), electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM) were used to analyze the microstructure and phase constituents, and the hardness, tensile strength, elasticity modulus and electrical conductivity were determined as well. The results showed that the Cu–3Ti–2Mg alloy is consisted of the β′-Cu₄Ti, Cu₂Mg and Cu matrix. After cold rolling, the grains of the studied alloy becomes longer and its microstructure becomes more homogeneous. The large number of β′-Cu₄Ti precipitate on the elongated grains adjacency and copper matrix after aging treatment. With the increase of aging time, β′-Cu₄Ti gradually transforms to β′-Cu₃Ti. The hardness, tensile strength and electrical conductivity are effectively improved through cold rolling and aging treatment. After 70% deformation and 450 °C aged for 3 h, the alloy can acquire the highest hardness, electrical conductivity and tensile strength, which are 357.6 HV, 18.5 %IACS and 401 MPa, respectively.