(西北工業(yè)大學 凝固技術國家重點實驗室，西安 710072)
摘 要: 采用氣壓浸滲法制備高體積分數(shù)的鍍TiC金剛石/鋁復合材料，通過SEM和EDS等手段對復合材料的斷口形貌進行分析，并研究TiC鍍層對復合材料界面和熱膨脹性能的影響。結果表明：TiC鍍層改善金剛石顆粒與鋁合金基體之間的選擇性粘結現(xiàn)象，斷裂方式以基體斷裂為主。部分TiC會被氧化成TiO2并與鋁合金基體反應生成Al2O3，從而實現(xiàn)金剛石顆粒與鋁合金基體之間良好的界面結合；TiC鍍層有效地降低復合材料的熱膨脹系數(shù)(CTE)，增強復合材料熱膨脹性能的穩(wěn)定性。在體積分數(shù)相同的情況下，CTE隨金剛石顆粒尺寸的減小而減小。
關鍵字: 復合材料；氣壓浸滲；鍍層；界面；熱膨脹
（State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:The TiC-coated diamond/Al composites with high volume fraction were fabricated by gas pressure infiltration. The fracture surface of the composites was analyzed by SEM and EDS, and the influence of titanium carbide coating on the interfacial bonding and thermal expansion of the composites was investigated. The results show that the TiC coating is proved to improve the selective interfacial bonding between diamond particles and Al alloy matrix, and the ductile rupture of the matrix is the main facture mechanism. Part of the TiC coating is oxidized to TiO2 and then reacts with Al to produce Al2O3 and thus to achieve the better interfacial bonding between diamond particles and Al alloy matrix. The coefficient of thermal expansion (CTE) of composites is decreased and stabilized due to the TiC coating. For the same volume fraction, the CTE of composites decreases with the decrease of the particle diameter.
Key words: composites; gas pressure infiltration; coating; interface; thermal expansion
