Research on the hot deformation behavior of Cu-20 wt%W composite under different temperatures

In this article, in order to study the hot deformation behavior of Cu-20 wt%W composite and reveal the strengthening mechanism of W particles, Cu-20 wt%W composite with a high relative density of 94.87% was prepared via spray drying technology and spark plasma sintering method. The tungsten particles have a good bond with the copper matrix because of the diffusion layer. Thus the Vickers hardness of Cu-20 wt%W composite is 120 HV, which is 110.52% higher than that of pure Cu, and the compression yield strength of Cu-20 wt%W composite at room temperature is 338 MPa, 338.96% higher than that of pure Cu. Meanwhile, the hot deformation behaviors of Cu-20 wt%W and Cu samples at 300–600 °C with a strain rate of 0.01 s-1 were studied in detail, and the critical strains of dynamic recrystallization were calculated. The tungsten particles can pin and accumulate the dislocations to result in high dislocation density and high recrystallization force, thus the critical strain values of Cu-20 wt%W composite under different temperatures are lower in comparison with the corresponding values of Cu. Furthermore, the Cu-20 wt%W composite is not as sensitive as Cu samples to elevated temperatures, and the tungsten particles can improve the high-temperature stability of Cu–W composites. When the deformation temperature is 300 °C, the peak stresses of Cu and Cu-20 wt%W composite are 198.44 MPa and 223.46 MPa respectively, and the peak stress value of Cu-20 wt%W composite is only 12.61% higher than that of Cu. However, when the deformation temperature rises to 600 °C, the peak stress percentage increment in Cu-20 wt%W composite compared with pure Cu increases to 128.37%.