Study of the Structure of Filler Composite Wire for Surfacing Wear-Resistant Layers

Abstract

The quality and properties of the deposited wear-resistant layers depend on the technological modes of surfacing and the type of filler materials used. The results of studying the structure of filler composite wire for surfacing wear-resistant layers are presented. Wire based on an aluminum alloy (hypereutectic silumin), silicon carbide (SiC) powders, and titanium intermetallic compound (Ti₂NbAl) is produced using powder metallurgy. The powders of SiC or Ti₂NbAl (taking into account their content in the final material of 5 wt %) and the matrix silumin alloy prepared in the form of chips are processed in a planetary mill. The wire is obtained by hot extrusion after holding the prepared components at a temperature of 600°C. Tribological tests of samples are carried out under dry sliding friction conditions (the friction coefficient is recorded continuously during tests). It is shown that the selected extrusion modes and preliminary preparation of the material in a planetary mill make it possible to obtain a pore-free compact material. An analysis of the structure of the resulting material and the character of distribution of reinforcing discrete powders reveals that Ti₂NbAl particles are uniformly distributed over the cross section of the wire, while SiC particles are practically absent in the central part and are concentrated along the periphery of the cross section. The results can be used for the application of composite wire as a filler material. Data on the character of distribution of reinforcing fillers should be taken into account when selecting schemes and modes of arc surfacing processes.