【摘要】 以Al-TiC混合粉末为原材料,采用激光表面合金化技术,在电解镍基材表面原位合成了TiC增强Ni3Al基复合涂层,分析了涂层的显微组织结构,通过溶解热力学计算研究了TiC的溶解及析出规律,对比了原始TiC粉末与原位析出TiC颗粒的形貌特征。结果表明:涂层主要由金属陶瓷相TiC及金属间化合物Ni3Al组成,激光表面合金化过程中,原始TiC粉末在Ni-Al合金熔体中发生溶解,然后在合金熔池中重新凝固析出,以原位增强颗粒的形式弥散分布于Ni3Al金属间化合物基体上,原位析出的TiC增强颗粒尺寸显著小于原始TiC粉末。更多还原

【Abstract】 Al-TiC powders blend was used as precursor material for in situ synthesizing TiC reinforced Ni3 Al matrix composite coating on electrolytic nickel substrate by laser surface alloying technique.Microstructure of the composite coating was analyzed.Dissolution and precipitation behavior of TiC phase were investigated by means of thermodynamic calculation.Morphology features of the as-received TiC powders were compared with the in situ precipitated TiC particles.Results show that the composite coating mainly consists of TiC metal ceramic particles and Ni3 Al intermetallic compound phase.During the laser surface alloying,the as-received TiC powders were dissolved into the Ni-Al alloy melt firstly,then TiC as in situ reinforcement particles were precipitated from the melt and were evenly scattered in the Ni3 Al matrix.The dimension of the in situ precipitated TiC particles was significantly smaller than that of the as-received TiC powders.更多还原