中文摘要：

以Al80/Ti20（mass%）混合粉末为原料,采用冷喷涂法在低碳钢上沉积致密的Al/Ti基复合材料,对其在不同温度下（400、450、500、550和600℃）进行热处理,获得原位Al_3Ti金属间化合物颗粒增强Al基复合材料。采用扫描电镜、X射线衍射仪、显微硬度仪及磨损试验机研究了冷喷涂Al/Ti复合材料热处理前后的微观组织形貌、相结构、硬度及磨粒磨损性能的变化规律。结果表明：冷喷涂Al/Ti复合材料的相结构与喷涂粉末相同,涂层组织致密、颗粒间为机械结合;Al/Ti复合材料在450℃热处理后其局部区域开始通过扩散反应原位形成Al_3Ti金属间化合物,而在600℃热处理后初始Ti颗粒已全部转变为Al_3Ti金属间化合物颗粒,同时,涂层内部颗粒界面间结合显著改善,从而获得原位Al_3Ti/Al复合材料。随着热处理温度升高,原位Al_3Ti/Al复合材料硬度先下降后升高,而其磨粒磨损性能则在550℃热处理后显著增加。

英文摘要：

Dense Al/Ti matrix composite coatings were deposited on low carbon steel surface by cold spraying using Al80/Ti20 （mass%） mixture powders as raw materials, and then the in-situ Al3Ti intermetallic compound particles reinforced AI matrix composites were obtained by heat treatment of Al/Ti matrix composite at different temperatures. The microstructure, phase, microhardness and abrasive wear performance of cold-sprayed Al/Ti composite coatings before and after heat treatment were characterized by means of scan electron microscopy （SEM） , X-ray diffraction （XRD） , Vickers hardness test and abrasive wear test. The results show that the as-sprayed Al/Ti composite coatings exhibit dense mierostructure and have the same phase structure as that of the spraying powder, and Al and Ti particles in the as-sprayed coating are mechanically bonded. After heat treatment at 450℃ , the local area of the Al/Ti composite begins to form in- situ AI3Ti intermetallie compounds by AI and Ti particles diffusion reaction, and after heat treatment at 600℃ , initial Ti particles have been completely converted to Al3Ti intermetallic compound particles. At the same time, the bonding between the particles in the coating is improved significantly, so as to obtain the dense in-situ Al3Ti/Al composites. The microhardness of the in-situ AI3Ti/Al composite coatings firstly decreases and then increases with the increasing of heat treatment temperature, and its abrasive wear resistance is significantly improved after heat treatment at temperature higher than 550℃.