Effect of heat treatment on mechanical properties and the structure of the tin-free aluminum bronze

Abstract

Nowadays bronze products have quite high demand, for example, bronze liners, bushings, flanges, etc. Bronze is a rather malleable antifriction material with good corrosion resistance. Depending on the different methods of melting and processing bronze, it is possible to increase strength properties and reduce cost of production of bronze products. There are various types of tin-free bronze, such as aluminum, lead, beryllium, manganese, magnesium, chromium, zirconium, cadmium, silicon, bronze. In this article, cast tin-free bronzes produced by two casting methods, such as casting in a casting mold and casting on gasifiable models (CGM), are considered. The advantages and disadvantages of each method are analyzed. Experimental regimes of heat treatment during CGM were developed and tested. The tests of mechanical characteristics are carried out on prototypes and a full-fledged liner that is used in the nodes of a spindle device. The microstructure of samples during CGM before and after heat treatment is studied. Dependence of time resistance, relative, elongation, hardness and impact toughness on various heat treatment modes was studied. A general comparative analysis of mechanical properties depending on the method of melting and processing of bronze samples was also carried out. The economic calculation was carried out, which revealed the economic effect of CGM with further heat treatment. The heat treatment regimes have been developed, which make it possible to use the CGM casting method for inserts with obtaining mechanical properties at the level of casting into the mold according to GOST 493‒79