Effect of B₄C Particulates Addition on Wear Properties of Al7025 Alloy Composites

摘要

In the present work, an attempt has been made to develop and study the wear properties of Al7025-B₄C reinforced aluminum metal matrix composites. The composites were prepared by using liquid metallurgy technique. Al7025 alloy was taken as the base matrix to which B₄C particulates were used as reinforcements. 3 and 6 wt. % of B₄C particulates were added to the base matrix. For each composite, reinforcement particles were pre-heated to a temperature of 500 degree Celsius to improve wettability and distribution. The microstructural study was done by using scanning electron microscope, which revealed the uniform distribution of particles in matrix alloy. A pin-on-disc wear testing machine was used to evaluate the wear rate, in which a hardened EN32 steel disc was used as the counter face. The results indicated that the wear rate of the composites was lesser than that of the Al7025 matrix. However, the material loss in terms of wear rate increased with the increase in load and sliding speed both in case of composites and the alloy. The worn surfaces were characterized by SEM microanalysis to know the different wear mechanisms.