The enhancement of wear properties of squeeze-cast A356 composites reinforced with B ₄C particulates

Abstract

In the present study, squeeze-cast A356 matrix composites reinforced with B ₄C particles were prepared and different volume fractions of B ₄C particles of various sizes were incorporated into the aluminum alloy by a mechanical stirrer.

Wear properties of the unreinforced alloy and composites with different vol.% of boron carbide particles were measured and compared. It is noted that composites exhibit better wear resistance compared to the unreinforced alloy. According to the differences in wear rates of the composites, two separate wear-rate regimes were identified as low- and high-wear-rate regimes.

It is observed that all the composite samples reinforced with 1 μm B ₄C particles show high wear-rate, regardless of the particle volume fraction. However, none of the samples containing 50 μm particles display this type of wear regime. Microscopic examination using a scanning electron microscope equipped with an energy-dispersive spectrometer, was carried out on the worn surfaces, subsurfaces, and debris. Rough and smooth regions are distinguished on the worn surface of the composites similar to the unreinforced alloy.