Temperature Gradient and Solidification Rate Simulation Model of the Microstructure of Laser-Cladded 27SiMn

In this study, 27SiMn was selected as a substrate, and the powder was a self-made iron-based alloy. Further, the thermophysical properties of the material were predicted by the CALPHAD phase diagram algorithm. In order to verify the accuracy of the numerical model, 10 sets of experiments were set up. The agreement between the results from the model calculations and the experimental results was 92%. Through the study of energy distribution in the laser cladding process, it was found that about 10% of the laser energy was used to heat the substrate to form a melt pool, and at least 53% of the energy was radiated into the environment. Finally, the effects of the temperature gradient and solidification rate on the microstructure of the cladding layer were explored. The numerical simulation results are helpful in predicting the solidification rate, temperature distribution and microstructure of the melt pool, thereby reducing the cost of testing as well as the time for the experimental method of trial-error.