Investigation of temperature field for the in-situ fabrication of particle-reinforced alumina ceramics coating via laser induction

Laser-induced aluminum thermal reaction was used to prepare a new iron particle reinforced alumina ceramic coating on the surface of TC4 titanium alloy. The aluminum thermal reaction heat generation in the on-line laser melting and coating process is fast and not easy to control, and its effect on the coating quality is unknown and usually neglected in the preparation process. In this paper, a numerical simulation model of a dual heat source containing the reaction heat is established. The temperature field of the new Al2O3-Fe composite coating and the thermal stress distribution pattern of the components were investigated. The effects of different laser parameters on the maximum molten pool temperature, thermal deformation and coating morphology of TC4 titanium alloy substrates were also discussed. The accuracy of the model is verified by the joint temperature acquisition experiment, which provides a reference for the selection of laser cladding process parameters. The simulation results show that the maximum temperature and volume of the melt pool increase significantly due to the coupling of the induced reaction heat, and the maximum temperature is not inversely proportional to the laser scanning speed, but directly proportional. The residual stress analysis shows that the residual stress on the coating is mainly the tensile stress along the laser cladding direction, which is the main reason for the transverse crack of the single layer coating after laser cladding.