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In process of non-isothermal forging system, phenomenon of heat transfer plays an important role in metal deformation. The heat transfer coefficient between die and workpiece, generally, is not constant and can not be obtained by experiment or other methods. For the purpose of predicting precisely the shape of workpiece, it is important to investigate the factors affecting contact heattransfer coefficient. In this article, the inverse analysis based on the direct sensitivity coefficient method is extended to deal with two- dimensional transient heat conduction problems with mixed boundary conditions by using Laplace transform and finite element techniques. It provides a powerful and reliable method to evaluate the value of contact heat transfer coefficient by measuring the temperature inside the die. Consequently, the heat flux through interface and the temperature distribution inside the workpiece can be completely evaluated.Mechanical model of this forming processes is then dealt with by using thermal-viscoplastic analysis and finite element method. Finally, the distributions of stress, strain, strain rate and theshape of workpiece inside the workpiece can be obtained.
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