Optimization on the diode laser joining process of Al2O3 liners

Abstract

The effects of fillers width and energy density of laser on weld morphology were studied. The mullite filler with the quality ratio of 70wt.% Al2O3-30wt.% SiO2 was determined as the initial fillers for the joining of Al2O3 liners according to the crystalline phase of Al2O3 liners. The transient multiple physical model of diode laser joining Al2O3 ceramic liners was built by Multiphysics COMSOL, and the coupling of temperature and stress field was carried out. The thermodynamic properties of the Al2O3 liners and fillers were analyzed and tested. Numerical results showed that the increase of fillers width would effectively reduce the thermal stress of the joint. With the increase of the energy density, the temperature and thermal stress of the seam zone increased gradually. With the increase of laser joining heat input, weld penetration increased slowly and then sharply. The experimental results indicated that the weld zone free from pores and macro cracks can be formed with the fillers width of 3mm, laser power of 700W and welding speed of 1mm/s.