镀TiC金刚石/铝复合材料的热膨胀性能

Thermal Expansion Behevior of TiC-coated Diamond/Al Composites

采用气压浸渗法制备了金刚石体积分数为65%的铝基复合材料,分析了复合材料的显微组织并对热膨胀系数(CTE)进行了测试,研究了镀TiC金刚石/铝复合材料的热膨胀性能。结果表明,金刚石颗粒在铝合金基体中分布均匀,组织致密;TiC镀层有效地改善了金刚石颗粒与铝合金基体间选择性粘结现象,增强了金刚石与基体间的界面结合;镀TiC使复合材料热膨胀系数明显降低,Turner模型和Kerner模型的均值可以预测其热膨胀系数,而对于未镀层的复合材料则可以用Kerner模型进行预测。

The TiC-coated diamond/Al composites with 65% diamond in volume fraction were fabricated by gas pressure infiltration method.The microstructure and coefficient of thermal expansion（CTE） were analyzed and measured,respectively,to understand the thermal expansion behavior of the TiC-coated diamond/Al composites.The results show that the uniform distribution of diamond particles in the Al alloy with compact microstructure can be observed.The TiC coating is considered to improve selective interfacial bonding between diamond particles and Al alloy effectively and enhance the interfacial bonding.The CTE of the composites is decreased obviously as a result of TiC coating.The CTE of composites with TiC coating can be predicted by the mean value of the Turner and Kerner models,while the CTE of the composites without coating can be predicted by the Kerner model.