Influence of hot-pressed sintering temperature on properties of SiCp/Al composites

Abstract

SiCp/Al composites were prepared by hot-pressing sintering method, and the effect of sintering temperature on the properties of the composites was studied. The phase compositions, relative density, mechanical properties and micro morphology of the composite samples were analyzed through X-ray diffraction, Archimedes drainage method, the three-point bending method and scanning electron microscope. Additionally, the thermal conductivity and thermal expansion coefficient were measured. The results show that SiCp/Al composites are composed of SiC, Al and Mg2Si phases. The addition of Mg improves the wettability between the matrix and SiC particles. With the increase of sintering temperature, the hardness and bending strength of the composites first increase and then decrease, reaching the maximum values of 98 HRB and 275 MPa at 700 ℃, respectively. The thermal conductivity of the composites first increases and then decreases, and the thermal expansion coefficient first decreases and then increases, reaching the maximum value of 218.187 W/(m·K) and the minimum value of 8.6 × 10−6 K−1 at 700 ℃, respectively.

Keywords

• sicp/al composites
• hot-pressing temperature
• mechanical properties
• microstructure
• thermal properties