DEVELOPMENTS OF THE INSTITUTE:: TECHNOLOGICAL PROCESS FOR PRODUCTION OF BILLETS OUT OF METAL LAYER COMPOSITE MATERIALS BY THE LIQUID METAL CLADDING METHOD

Application area

This process results in metal blanks with new, often incompatible requirements, which can not be obtained using one metal or an alloy. The blanks of this kind are necessary for production of bushings, nuts, thrust rings and other parts with antifriction properties for high load mechanisms. These blanks can be used for production of bushings for automobile half-trailers, bearings for guillotine shears, calender shafts, cone-type crushers, pulling wheels of excavating machines, and other mechanisms.

Technical characteristics

The essence of this technological process for obtaining new materials, whose properties differ essentially from properties of their components, is in composition of several materials in a single structure. For example, steel bushings clad with aluminum or lead- aluminum bronze (7 … 10 % Al, 2 … 3 % Fe, 1 … 3 % Mn, 1 … 3 % Pb, Cu-the rest). To form the permanent strong and tight joint of layers, the process involves manufacture of a steel envelope in the form of a ring, filling-up of a cavity of the horizontally located envelope by a powder mixture, its preheating to a temperature of 610 … 730°С and rotation of the steel envelope until mixture particles are melted and a protective slag layer is formed. Then, cladding metal at a pouring temperature of 1080 … 1120°С is poured in a cavity of the steel envelope coated with a protective slag layer, this cavity being used as a crystallizer. After cooling the steel envelope to a temperature of 710 … 760°С, the cladding metal solidifies. The formation of the joint of components of a metal layer composite material terminates in no other than setting of contact surfaces or formation of common grains or new phases in a joint zone.

Advantages

The process provides clad layers with high purity on oxygen and nonmetal inclusions, high quality of layer's joint, and large uniformity of thickness of the clad layer. The important advantage of the method is the possibility to obtain metal layer composites with a wide range of layer's thickness. The process is cost-effective, simple, and suitable for obtaining cheap types of products from metal layer composite materials.