Structure and mechanical characteristics of the hypereutectic silumin subjected to pulsed electron beam treatment

Abstract

Silumin, aluminum with silicon alloy, is a promising material used for the manufacture of medium-loaded machine parts and mechanisms. High brittleness is one of the main drawbacks of hypereutectic silumin. Modification of a hypereutectic silumin (18-20 wt.% Si) was carried out by irradiating the samples with an intense pulsed electron beam. It was established that irradiation of cast hypoeutectic silumin by an electron beam leads to a significant reduction in the number of micropores, forming a high-speed cellular crystallization structure with a cell size of (0.4-0.6) [mu]m. An irradiation mode allowing to increase the silumin surface layer hardness by more than 4 times, wear resistance - by 1.2 times, to increase ductility by 1.2 times in relation to the initial material was detected (35 J/cm{2}; 200 [mu]s, 20 imp. 0.3 s{-1}).