SUMMARY

With a high demand for products made of Inconel 718 in industries of aerospace and automobile, performance analysis becomes more important for the machining process of Inconel 718 such as laser-assisted milling. The performance can be evaluated in terms of several target performances from the perspective of finished workpiece including surface roughness, residual stress, and ultimate tensile strength, or from the perspective of milling process including temperature in shear zone and tool wear. Surface roughness characterizes the surface texture in terms of deviations. Residual stress is created under mechanical load, thermal gradient, and phase change, which significantly affects the damage tolerance and fatigue performance of product. Ultimate tensile strength is a classic material properties to examine its capacity to withstand loads tending to elongate. Temperature in shear zone is the results of both laser heating and thermal loads during milling. Moreover, tool wear describes the gradual failure of cutting tools due to regular operation. All these quantities are selected due to their importance in the evaluation of laser-assisted milling process. On one hand, people are interested in knowing the performance under designed process parameters such as tool geometry, laser power, feed rate, and cutting depth. For this study, the analytical models are planned to be built to predict the resultant temperature under laser heating and machining, residual stress profile of machined surface with original residual stress present, surface roughness of bottom surface, ultimate tensile strength, and tool wear in laser-assisted milling of Inconel 718, in addition to numerical simulation of temperature and residual stress. On the other hand, people want to know the possible combination of process parameters to achieve required target performance. Therefore, inverse analysis is proposed on residual stress, surface roughness, and ultimate tensile strength.