Tribological properties of novel Al 7075(T6)-SiC-crumb rubber-MoS2-based hybrid composites: An experimental approach towards green revolution

Abstract

In the present study, an experimental approach is conducted for analyzing the tribological attributes of the novel green hybrid metal matrix composites fabricated by an advanced vacuum-sealed bottom pouring stir casting comprised of Al 7075(T6) as a base metal doped with three distinct reinforcements as silicon carbide, crumb rubber, and molybdenum disulfide. Six casting process variables such as SiC, crumb rubber, MoS2, stirring speed, stirring time, and pouring temperature have opted for the fabrication of green hybrid composites via Taguchi L18 mixed-level orthogonal array. Tribological studies (in terms of wear loss, frictional force, and coefficient of friction) on fabricated green composites are examined via the high-temperature rotary pin-on-disc tribometer with fixed process parameters (such as wear track diameter, sliding speed, normal load, sliding distance, disc rotation speed, and test duration) under dry sliding wear test. Moreover, the wear test is also executed under variable temperature conditions of 35 °C, 100 °C, 200 °C, and 300 °C. The metallography of synthesized green composites and their worn surfaces is inspected via a metallurgical microscope and scanning electron microscopy–energy dispersive X-ray spectroscopy techniques. Besides, the analysis of variance is implemented to predict the percentage contribution of the combined process variables for wear loss analysis. In contrast to the as-cast specimen (S0), the developed hybrid pin specimen (S3) yields a tremendous improvement in its metallurgical and tribological attributes under varying temperature conditions. Owing to the merits of the proposed composite, it can be extensively used in lightweight, high-temperature, and wear-resistant applications of various automotive and aerospace engineering.