氧化锆增韧机制在激光熔覆技术中的应用

Application of Zirconia Toughening Mechanism on Laser Cladding

陶瓷粉末氧化锆在激光熔覆技术中的主要增韧机制有相变增韧和弥散增韧,将其作为增韧相以适当的比例添加到钴基合金粉末(Stellite-6)中,选择合适的工艺参数,在钛合金TA15表面制备出了掺杂5%(质量分数)氧化锆的钴基合金涂层。实验结果表明:含有氧化锆的钴基合金涂层的晶粒得到细化,组织均匀分布,涂层的致密度得到提高;含有氧化锆熔覆层中的裂纹得到了修复,熔覆层的组织性能得到改善,X射线衍射的分析也证实了熔覆层中存在单斜相的氧化锆,即发生了相变增韧;同时氧化锆的加入提高了熔覆层的显微硬度和耐磨性,从而为改善激光熔覆层的性能提供了一定的参考。

Transformation toughening and dispersion toughening are the main toughening mechanisms on zirconia.Zirconia is used as the toughening phase of laser cladding layer,and the TA15 titanium alloy is selected as substrate on which the cobalt-based composite powder（Stellite-6）with 5%（mass friction）of ZrO2 is cladded.The results indicate that zirconia can refine and purify the microstructure of the coating and improve compactness of the coating to some extent.Moreover,the cracks which appear in the coating have been repaired,the microstructure of the coating has been improved.The X-ray diffraction spectrum has proved phase structure of zirconia ceramic in the coating is monoclinic,which has indicated the appearance of transformation toughening.The microhardness and wear resistance of the coating have been improved with the addition of zirconia.This study offers some references for improving the quality of laser cladding layer.