Finite-Element Model of Bimetal Billet Strain Obtaining Box-Shaped Parts by Means of Drawing

The article shows data on determining billet shape while obtaining a box-shaped part from aluminum-copper bimetallic composition. Special attention in the course of finite-element modeling of strain process is paid to the choice of mechanical characteristics of each layer and the nature of the relationship between layers. It is shown that the optimal billet shape for drawing is a “rectangle with cut angles” and copper layer outer position. This billet shape ensures the absence of corrugations with a single junction drawing of aluminum-copper bimetal box-shaped parts, and also provides the least deformation force with minimum intensity of stresses and strains. The absence of folds allows to judge on sufficiently proportionate layer-by-layer strain and preservation of the indissoluble layer-by-layer engagement. This makes possible to design a technological process for the production of bimetallic contacts with the required set of electromechanical characteristics and to recommend it for manufacturing. It is also noted that a more solid and consistent material for obtaining the optimum product handling properties should be located on the outer layer of the part. At the same time, it is advisable to use drawing in the manufacture of bimetallic parts to select, whenever it is possible, materials with approximately the same strength and plastic characteristics, avoiding the occurrence of different stresses in the product layers and, accordingly, distortion or other negative consequences for the finished item. The presence of lamination in a bimetallic composition increases the electrical resistance hundredfold and leads to the product rejection.