Abstract:

Due to the great complexity of the block-type cold forging process,it is difficult to obtain the best forging parameters by optimizing the metal filling ability and the forming force only at a process stage. In order to solve this problem.a multi-objective optimization method based on the forming process is put forward. In this method,the finite element simulation and the orthogonal test are combined to achieve the best metal filling ability at the basic
forming stage. Thus,the metal filling ability is optimized and a set of relevant process parameters is obtained. Then,the fitting optimization method based on objective function values is employed to analyze the relationship between the flash slots height and the drop quantity of punch. Thus,the forming force is optimized through controlling the flash slots height to achieve the minimum forming force at the last filling stage,and a set of optimum process parameters that simultaneously ensures the best metal filling ability and the minimum forming force is determined. Through the above-mentioned statements,the metal filing ability and the forming force are optimized at different stages,and the optimized results accord well with the physical experimental ones. It is demonstrated that,as the proposed method fully considers the forming characteristics of the block-type cold forging,it helps to obtain more accurate and reasonable forging parameters with simplicity.

Key words: block-type cold forging, metal filling ability, forming force, multi-objective optimization