Compositional Design of Ceramic Extrusion Die Materials based on the residual stress analyses in the Die Manufacturing Process

摘要

In the die manufacturing process of ceramic extrusion die, the residual stress was produced resulted from the thermal expansion coefficient mismatch between ceramic die and die core of graphite. As a result, the longitudinal cracks were formed in the ceramic extrusion die. The thermal residual stress formed in the cooling process was analyzed by finite element simulation method. The result indicated that the thermal expansion coefficient was the primary factor which could affect the tensile stress of ceramic extrusion die. Then, the thermal expansion coefficient, elastic modulus and poisson's ratio of ceramic extrusion die material were selected as design variables, and the largest tensile stress that less than allowable stress of ceramic die material was determined as the objective function, the material component were optimized according to the finite element simulation. The longitudinal cracks were eventually avoided.