Closed Loop Control of 3D Laser Cladding Based on Infrared Sensing

In this paper, a heat input closed-loop control system based on infrared image sensing for 3D laser cladding is introduced. A high frame-rate (up to 800 frames/s) camera is installed coaxially on the top of the laser-nozzle setup. Complete of the infrared images of the molten pool can be acquired with a short nozzle-substrate distance in different scanning directions, eliminating the noise from the metal powder. The characteristics of the images show a clear relationship with the parameter variations of the cladding process. A closed-loop control system is built based on the feedback of the infrared image sensing. The control results show a great improvement in the geometrical accuracy of the part being built