MODELING OF THE EFFECT OF PATH PLANNING ON DEPOSITION OF METAL-CERAMIC COMPOSITE WITH LASER POWDER DEPOSITION PROCESS

摘要

A finite element model, coupled with a thermo-kinetic model is developed to simulate the heat transfer and microstructural evolution in laser deposition of a metal-matrix composite powder. The model is used to predict the final hardness and the effect of process parameters on a metal matrix. A defined area is covered by H13-WC powder with three different deposition patterns: one-section, two-section, and three-section. The one-section pattern is the normal deposition pattern in which the deposition area is covered with zigzag patterns and in one step. In the two- and three-section patterns, the deposition area is divided to two and three sections, respectively, and is covered in two and three steps. The finite element model is used to determine the temperature history of the process used in the kinetic model to analyze the tempering effect of the heating and cooling cycles of the deposition process on the composite matrix. The results show that dividing the area under deposition into smaller areas can influence the phase transformation kinetics of the process and, consequently, change the final hardness of the metal matrix. The two-section pattern shows a higher average hardness than the one-section pattern, and the three-section pattern shows a fully hardened surface without significant tempered zones with low hardness. The simulation results are in very good agreement with the experimental ones.