Michel Galopin

Modeling and Sensitivity Study of the Induction Hardening Process

Induction heating is a case hardening process used to improve performance of machine components by producing a hard martensitic microstructure and high compressive residual stresses at the surface layer. A reliable numerical model able to predict the hardness profile would shorten process development. However, the accuracy and the efficiency of the model are restricted by the coupling complexity between the electromagnetic and thermal fields, and the nonlinear behaviour of the material properties. The paper analyzes the sensitivity of the material properties values and of the finite element meshing onto the predictive modeling of the case hardening profiles. The material used is SAE-4340 low-alloy steel. The simulations are done using a computer-modeling software (Comsol) and the sensitivity analysis is conducted by using an experimental design method.

An integrated computer-aided optimization system for process planning

Abstract Designing a manufacturing operation is a major activity of process planning, especially in the case of processes requiring a comprehensive selection of the operating parameters. This activity includes three hierarchical stages : procedure design, schedule design, and tolerance design. A new approach for process modelling and optimization has been devised to address the problems to solve at each stage. The methodology is based on sequential experimentation to model the feasible domain of the process and on a direct search technique to optimize for quality and process robustness. An integrated computer-aided system has been designed to manage the manufacturing data and the strategies for optimization and variation reduction. Applications to various manufacturing processes are presented.

Development of a novel robotic wrist F/T sensor and its implementation in the grinding operation

Grinding is one of the most complex and unpredictable metal- removing processes. Based on the in situ repairing operation in turbine blades, this paper presents a novel welding and grinding system, which consists of a portable robot and its control system, a novel waist F/T sensor and its control system, camera and image processing card, welding gun and grinding well. The robot can be moved and can be conveniently operated by one man. At the same time, it is fit into a 600 mm hole (access hole) and can reach over 90% of the total blade surface. Its productivity increases three times compared to man operation.