The excellent combination of strength and ductility in W particle-reinforced Cu matrix composites via hot rolling conditions adjustment
Hongyi Song, Qingqing Liu, Ningyu Li, Daohan Yu, Yuxiang Chen, Yueming Huang, Mingyang Li, Yongqin Chang
Abstract
In order to obtain high performance (e.g. the tensile strength and elongation) of Cu-W composite, Cu-15 wt% W composite was fabricated by ball milling, spark plasma sintering and subsequent hot rolling. The study investigated the effects of the rolling temperature (650 ℃, 750 ℃ and 850 ℃) and the rolling reduction (50 %, 65 % and 80 %) on the microstructures and tensile properties of the composite. This composite rolled at 650°C with the rolling reduction of 65 % exhibits the ultimate tensile strength of 717 MPa and the total elongation of 13.2 %. The ultimate tensile strength of the composite at the optimum hot rolling condition (650°C-65 %) is up to 111 MPa higher than other Cu-15 wt% W samples at other hot rolling conditions, while the total elongation is maintained without significant reduction. The 650°C-65 % condition results in the relatively high proportion of recrystallized grains with the size of 0.27 μm. The excellent performance of the composites is also attributed to the fine, high-density and diffusely reinforcing nanoscale W particles within Cu matrix. The nanoscale W particles hinder the grain boundaries migration and dislocations movement through the Zener pinning effect. Introducing nanoscale beneficial particles and adjusting hot rolling processes significantly enhance dislocation strengthening and grain refinement in Cu-15 wt% W composite. Our study contributes to the development of W particle-reinforced Cu matrix composites with high strength and ductility.