中文摘要：

采用气压浸渗法制备金刚石/碳化硅/铝复合材料,研究复合材料的断口形貌以及界面反应,测试复合材料的热膨胀性能。结果表明：金刚石表面Ti镀层使得其选择性粘附不同于未镀钛金刚石的,而在各个面上均粘附有Al,金刚石与基体间有着良好的界面结合,断裂方式以基体断裂为主,其界面反应后,Ti以Al3Ti和Ti-Al-Si等金属间化合物的形式析出,提高金刚石/铝界面的结合强度,降低复合材料的热膨胀系数;随着金刚石颗粒粒径的增大,金刚石和碳化硅颗粒间粒径比的增大增加了整个复合材料的体积分数,从而降低了其热膨胀系数;金刚石颗粒粒径增大导致热膨胀系数升高。这两方面共同影响复合材料的热膨胀系数,但前者起主导作用;金刚石和碳化硅在不同配比下的热膨胀系数随着复合材料中碳化硅含量的增加逐渐增大,Terner模型与Kerner模型的计算平均值能较好地预测实验结果。

英文摘要：

The diamond/SiC/Al composites were produced by gas pressure infiltration,and the morphology of the fracture surfaces,interface reactions and coefficients of thermal expansion of the composites were investigated.The results show that the aluminum matrix adheres to all the faces of Ti-coated diamond,which is different from the selective adhesion phenomenon observed in the uncoated diamond composites,the interface bonding between diamond and aluminium matrix is strengthened due to the existence of Ti coating on the diamond surface,the main fracture mechanism of the composite is ductile fracture.After interface reactions,the intermetallic compounds,such as Al3Ti and Ti-Al-Si deposits,improve the diamond/Al interfacial bonding strength and decrease the thermal expansion coefficients of the composites.With the diamond particle diameter increasing thermal expansion coefficients of composite decrease due to the increasing,the particle diameter ratio of diamond and silicon carbide,which leads to the increase of volume fraction of composites.The thermal expansion coefficients of composites decrease with the increase of the diamond particle size.The two factors are interacted,however,the first factor plays a dominant role.The thermal expansion coefficients increase with the SiC content increasing at different content ratios of diamond to SiC.The experimental results can be well predicted with the average results calculated by Terner and Kerner models.