A new method for direct welding of alumina and zirconia ceramics by ultrashort pulse laser for high temperature application

Abstract

The direct welding of alumina and zirconia ceramics by ultrashort pulse laser is presented for the first time. Compared to traditional dissimilar ceramic joining techniques such as brazing and diffusion welding, this method shows various advantages, including operation at room-temperature, higher welding efficiency, and negligible impact on base materials. The joint microstructure consists of a combination of Al₂O₃ and ZrO₂ phases, without new phases detected. By adjusting the laser focal point position, the phase content within joint is effectively regulated, successfully preventing crack formation in alumina substrate. The influence of laser power and welding speed on joint morphology and mechanical property is fully investigated. The highest four-point bending strength of 365.5 MPa and shear strength of 33.4 MPa are achieved. After experiencing thermal cycling test at 1000°C, the joint strength and microstructure does not exhibit significant changes, demonstrating the excellent high-temperature durability of the sample.