Influence of Spark Plasma Sintering Time on the Microstructure and Properties of High-Silicon–Aluminum Composite Materials

SPS (Spark plasma sintering) is characterized by a rapid heating rate, low sintering temperature, and short sintering time, which can effectively suppress the growth of the Si phase during sintering. This study investigated the influence of spark plasma sintering time on the microstructure and properties of high-silicon–aluminum composites. Ball-milled high-silicon–aluminum powder was sintered at 565 °C for different durations. The results showed that the sample sintered for 1 h exhibited the optimal microstructure and properties. Its thermal conductivity, coefficient of thermal expansion, and relative density were 134.6 W/m·K, 8.55 × 10–6 k–1, and 97.75%, respectively. Compared with the conventional hot-pressing sintering method, spark plasma sintering requires a shorter sintering time and lower sintering temperature, effectively suppressing the growth of the Si phase, refining the microstructure and improving material performance.