Modelling the Laser Cladding Process of M4 High Speed Steel

The manufacturing process of laser cladding of bulk and thin wall samples has been simulated with the academic non-linear finite element (FE) code LAGAMINE. This thermo-mechanical-metallurgical code developed in ULiege since 1984 accounts for all the interactions between the different fields (displacement, stress, temperature). Already used on the cladding of TA6V cases [1], the code is this time applied on the cladding of M4 powder. The predicted thermal field has been validated by thermocouple measurements as well as by the size of the melt pool measured by optical microscopy on cut samples. The thermal history allows predicting the maximum temperature in the melt pool as well as the number of times that the top layers are re-melted. These observations can be related with the observed microstructure (size, shape, and type of carbides) which generates different wear behavior. This thermal field explains the heterogeneity of the microstructure along the sample depth that could be seen on the micrographies. Both 2D and 3D simulations are presented. The thermo-mechanical simulations compute the stress and strain fields. The residual stresses are currently measured (X -ray and strain gage) to validate the results. A new shape of samples has been computed to allow an easy evaluation of the stress state through displacement measurements. [1] Tran, H., Tchuindjang, J.T., Paydas, H., Mertens, A., Jardin, R.T., Duchêne, L., Carrus, R., Lecomte-Beckers, J., Habraken, A.M., 2017. 3D thermal finite element analysis of laser cladding processed Ti-6Al-4V part with microstructural correlations. Mater. Des. 128, 130-142.