Reciprocal dry sliding wear behaviour of B4Cp reinforced aluminium alloy matrix composites

In the present work, AlSi9Cu3Mg alloy matrix composites reinforced with 15 and 19 vol% B4Cp were produced by squeeze casting route at 850 °C under low vacuum. Titanium-containing flux (K2TiF6) was used to promote the wetting between B4C and liquid aluminium metal. It was found, from the microstructural observations, that the wetting improved by the formation of a thin Ti-rich reaction layer. In order to investigate the wear properties, the samples were subjected to reciprocating wear tests against AISI 4140 pin under dry sliding conditions. The effect of B4C volume fraction, sliding velocity, applied load and sliding distance on reciprocal dry wear behaviour of composites was studied using general full factorial experimental design. The effects of factors and interactions on the coefficient of friction (COF) and the wear rate values of both composite specimens and counter materials were studied. Worn surfaces and wear debris were characterised using field emission gun scanning electron microscope (FEG-SEM), Energy Dispersive X-Ray Spectroscopy (EDS), optical microscope (OM) and X-Ray diffraction (XRD). From microstructural investigations, wear mechanism was suggested as a combination of adhesive, abrasive, and delamination wear.

► AlSi9Cu3Mg–15B4C and AlSi9Cu3Mg–19B4C composites were produced under low vacuum.
► Homogenous particle distribution and decreased porosity values were obtained.
► Effects of various parameters on the dry sliding behaviour of composites were studied.
► We find that volume fraction and load are the most important factors for COF and wear rates, respectively.
► We suggested the wear mechanism as a combination of adhesive, abrasive, and delamination wear.