为了研究激光高能量密度下纳米颗粒的生长情况,从而为优化工艺参数提供参考,在Brook晶粒生长经典理论基础上,结合有限元软件Ansys数值模拟的激光熔覆温度场,计算了激光熔覆等离子体喷涂预置纳米Al2O3+13%TiO2(质量分数)陶瓷涂层过程中纳米颗粒尺寸变化,并讨论了纳米颗粒初始尺寸及不同熔覆区域对其生长的影响。同时,对等离子体喷涂纳米涂层进行了激光熔覆试验。结果表明,纳米颗粒在激光熔覆试验中生长情况的总体趋势与理论计算结果基本一致,说明基于Brook理论的晶粒生长理论对了解纳米颗粒在激光熔覆过程中的生长有一定的理论指导意义。
In order to optimize the processing parameters of nanostructured coating during laser cladding, the changes of nanoparticles size under high energy density laser are investigated. Based on the Brook's classical theory about grain growth and temperature field of laser cladding with finite element software Ansys, the nanoparticles growth of laser-clad nanostructured Al2O3+13%TiO2 (mass fraction) coating prepared by plasma spraying are investigated. The effects of nanoparticles original size and laser-cladding region on grain growth are studied. Meanwhile, experiment of laser cladding on nanostructured Al2O3+13%TiO2 prepared by plasma spraying is carried out. The results show that the experimental overall trend of nanoparticles growth is consistent with the calculated result during laser cladding process, which indicates that the nanoparticles growth theory based on Brook's theory is correct and reliable. The theory provides theoretical basis for nanoparticles growth during laser cladding process.