Research On Laser Cladding Repairing

It's a good way to repair workpiece by using laser cladding. The laser cladding repairing layer has a good performance. When laser cladding was adopted to repair the equipment's parts, the property of these was improved and their lift time was lengthened and the evidence benefit has been obtained.The theoretics, process, microstructure and performance of laser cladding repairing experimentally and theoretically studied in this paper and main conclusions are as follows.The methods to calculate the interaction efficiency of laser and alloy powder are presented. Analytical model of the cross-section of the cladded coating and the dilution were established. By combining with theory of fast melting and cooling, analyzed the fact that the solidification microstructure would grow up towards equiaxed grain.These analytical models were calculated by theoretical methods and determined by means of metallography. The theoretical and experimental results coincide well with each other quantitatively and are consistent in reflecting the objective fact of the process. This model is helpful to find optimum process parameters, understand the major relationship between the process parameters and the results.Based on the surface macroscopical and microcosmic appearance of laser cladding layer, the article briefly demonstrates the main factors affecting the quality of laser cladding layer: laser power, scanning speed, the shape and the size of laser beam, thickness of prefabricated powder, overlapping rate, substrate material, cladding material and complication of environment. It also put forward the corresponding measures to improve the quality of laser cladding layer, and better relationship of process parameters in stainless steel coating on Q235 substrate was obtained which used in rotate product line for CR2025/2032 Li-Mn button battery.On the basis of processing investigation, distributing of alloy element, microstructure and hardness distributing characteristic of laser cladding layer were systematically studied by using light microscope and microhardness testing machine. In the present research, a new method was developed for measuring the residual stress of the laser cladding repairing material by microindentation hardness testing, which was conveniently and cheaper. Therelationship between residual stress and microhardness was studied, and a formula was given at last. That method was used for calculating the residual stress of laser cladding repairing layer, and there was good agreement between our experiment results and theoretical results.