Microstructures and mechanical properties of alumina whisker reinforced copper matrix composites prepared by hot-pressing and hot isostatic pressing

The single crystal alpha-Al2O3 fibre is an excellent reinforcement material for their excellent elastic modulus, high chemical and thermal stability. Copper matrix composites containing fixed amount alloys (Sn, Ni, Fe, etc) and different amounts of alumina whisker are prepared through mechanical alloying, hot-pressing and hot isostatic pressing. The results show that a solid solution structure is formed between the alloying elements and copper in which alumina whisker are uniformly distributed in the copper matrix. The compressive strength increases with the increase of Al2O3 whisker when the Al2O3 whisker content changes from 0.0 wt% to 1.5 wt%, and the maximum value reaches 288.26 MPa. The strengthening mechanism is fine grain strengthening and solid solution strengthening; besides, the dispersion mechanism and the mechanism of dislocation strengthening can also be exerted.