Zinc matrix composites prepared by ultrasonic assisted casting method

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ÎÄÕÂÒ³Â룺104 - 109

Key words£ºSiC_p/ZA27£» high-intensity ultrasonic£» mechanical properties£» strengthening mechanism

Abstract: By ultrasonic assisted casting method SiC_p/ZA27 composites with particle diameter of 0.520¤@¦Ìm, and volume fraction of 2%8% were prepared. The composites microstructure, effects of particles size and volume fraction on the composites properties and the function mechanism of high intensity ultrasonic in the melt were studied. The SiC particulates are uniform macro-distribution in the matrix. The TEM results show that the interface between SiC_p/ZA27 is planar without reaction products and precipitations, and there are lots of dislocations in the matrix. With the increase of the volume fraction and the size of the SiC particulates, the tensile strength, elastic modulus and Brinell-hardness of the composites increase, while elongation ratio decreases. Because of the small clusters of the micro-sized particles, the yield strength of the small diameter SiC particles reinforced composites is lower than that of the large diameter SiC partiles reinforced ones. The results show that the SiC/ZA27 composites with SiC particulates uniformly disperse in the matrix, and good cohesion between SiC_p and ZA27 is believed to be the result of the cooperative effects of acoustic cavitation and high speed acoustic streaming in ZA27 alloy melt.