Thermomechanical and metallurgical modelling of laser hardening and laser cladding processes

Resumo

The development of high stresses and distortions is one of the main concerns in laser surface heat treatments. The objective of the present thesis is to contribute to the better understanding of the thermomechanical behavior during laser transformation hardening and laser metal deposition techniques, including as well the development of a flexible tool with customizable models for the numerical calculation of the thermomechanical variables, and the microstructural evolution through phase transformation models. Such a tool will be useful for the prediction of the residual strains and stresses after the processes as well as the phase changes, helping with its optimization and understanding, thus reducing the number of test trials necessary to achieve the desired results. Something that has paramount importance when unique or expensive workpieces should be treated. The model was validated using several experimental techniques to assess its predictions and fine tune some of its parameters.