Combined laser-foundry manufacturing process of bimetals

An analysis of existing methods and a new combined process of bimetallic fabrication are presented, according to which a special regular macro relief is made on the surface of its functional component by laser or mechanical treatment. The bimetallic component thus prepared is placed in sand form, the dimensions of the cavity of which correspond to its dimensions. A melt of the structural component of bimetal is fed to the surface of the functional component through a hole in the form of a special device with a defined flow rate. The process of manufacturing bimetal, the functional component of which was a nickel alloy, and structural – carbon steel St.3Mathematical modelling and computing determine the patterns of temperature distribution over the height of the projections of the macro relief when they are heated by the melt of the structural component of bimetal, depending on their geometrical parameters, thermophysical characteristics of the material, schemes and conditions of pouring. Metallographic studies have established the conditions under which metallurgical bonds are formed between bimetal components and their bond strength is ensured. It is proved that to insure high bond strength of bimetallic components and uniform distribution over the joint plane, it is necessary that the height of the macro relief and the step between them have the optimum value. In this case, the transverse dimensions of the projections (1x1) mm, the optimal dimensions of the projection height are 0.5 mm, the steps between them - 1.5 mm. The high efficiency of the new, innovative combined technology of bimetal manufacturing has been demonstrated.