钛基体激光直接熔覆ZrO_2涂层实验研究

Experimental study of laser direct cladding of ZrO_2 coating on titanium substrate

采用激光同轴送粉工艺在钛基体上直接熔覆ZrO2陶瓷涂层,研究不同工艺参数对单道熔覆层熔覆质量的影响规律;采用光学显微镜观察陶瓷涂层的微观组织,并采用电子探针技术分析基体和ZrO2陶瓷结合区成分分布;利用XRD分析激光熔覆前后ZrO2陶瓷物相变化情况.结果表明:在一定的功率范围内,熔覆层宽度受激光功率的影响不大,熔覆层高度和基体熔化深度随工艺参数的变化呈现一定的规律性;ZrO2和Ti基体结合区形成很好的成分梯度渐变过渡,陶瓷微观组织为细小的枝状晶组织;激光熔覆ZrO2陶瓷后,单斜相(m相)衍射峰强度相对减弱.

Laser direct cladding of ZrO2 ceramic coating on titanium substrate was proceeded by coaxial powder feeding. The regularity Of influence of different process parameters on single-layer coating quality was studied; the microstructure of ceramic coating was evaluated using optical microscope, and the composition distribution in bonded zone of titanium and ZrO2 was detected using electron probe. The phase transformation between initial powder and coating was determined by X-ray diffraction. Experimental results show that the laser power has little effect on cladding layer width within a certain range, and the variation of cladding layer height and depth of substrate fusion has a regular pattern with process parameters change. Compositionally graded transition has been formed in ZrO2 and Ti bonded zone, and the microstructure of ceramic is a structure of fine dentrite. The monoclinic phase（m） reduces after ZrO2 is cladded by laser.