No abstract

Among numerous techniques to manufacture Aluminium metal matrix composites, the stir-casting route is employed for mass production because of less expensive. In this work, Al-7Si alloy-based composites reinforced with 10wt% graphite and x wt% of tin (x = 0, 2.5, 5, 7.5 and 10) microparticles are manufactured through the bottom pouring casting route. This study deals with the various effect of the mechanical properties, and wear resistance of Gr, and Sn particulates reinforced Al-7Si alloy matrix composite. The added Sn metal powder up to 7.5 wt.% was diffused in the lattice of hypo eutectic Al-7Si alloy and formed a solid solution. The hybridization of Sn with graphite in Al-7Si alloy matrix brought signi cant enhancement in the tribological and mechanical properties of the composites. The ductile mode of fracture in all the composites with tear ridges and dimples was noted. The wear rate and the coe cient of friction of the composites were decreased with the addition of Sn metal powder in the material system. The Sn metal powder surfaced during the wear process and formed a thin mechanically mixed tribo layer and reduced the friction. The thin mechanically mixed tribo layer at the interface restricted the direct contact of asperities in the mating surface and reduced the wear loss. Adhesive wear was found to be active in the composites with Sn metal powder.

In this research, tin was added to the AZ31/2Al2O3 magnesium metal matrix composite to investigate its influence on degradation rate in the presence of simulated body fluid (SBF) and wear behaviour in dry conditions. The AZ31- xSn/2Al2O3 ( x = 0, 2, 4, 6, 8, and 10 wt%) composites were manufactured using the bottom pouring stir casting route. The microstructure of the manufactured AZ31/2Al2O3 and AZ31- xSn/2Al2O3 composites revealed that they were composed of the α-Mg solid solution and the intermetallic compound □-Mg17Al12, which was situated near the grain boundaries. When tin was added, the Sn-rich intermetallic compound Mg2Sn was formed, increasing the volume fraction of the Mg2Sn phase. Compared to AZ31/2Al2O3 composite, the wear test revealed that AZ31/2Al2O3 composites containing Sn particles exhibited a higher ability to generate more stable tribo-layers at higher applied loads, which protected the worn surface and reduced the wear rate. The wear resistance of composites was improved primarily by the behaviour of the tribo-layer in the wear process. The degradation rates (mm/year) of the AZ31 composites were carried out for 72 h in SBF. The degradation rate was reduced when the Sn content in the AZ31/2Al2O3 composite was increased to 6 wt% and then increased with further Sn addition. It was observed that when the amount of Sn particles increases up to 6 wt%, the severity of the degradation decreases.

No abstract

Among numerous techniques to manufacture Aluminium metal matrix composites, the stir-casting route is employed for mass production because of less expensive. In this work, Al-7Si alloy-based composites reinforced with 10wt% graphite and x wt% of tin (x = 0, 2.5, 5, 7.5 and 10) microparticles are manufactured through the bottom pouring casting route. This study deals with the various effect of the mechanical properties, and wear resistance of Gr, and Sn particulates reinforced Al-7Si alloy matrix composite. The added Sn metal powder up to 7.5 wt.% was diffused in the lattice of hypo eutectic Al-7Si alloy and formed a solid solution. The hybridization of Sn with graphite in Al-7Si alloy matrix brought significant enhancement in the tribological and mechanical properties of the composites. The ductile mode of fracture in all the composites with tear ridges and dimples was noted. The wear rate and the coefficient of friction of the composites were decreased with the addition of Sn metal powder in the material system. The Sn metal powder surfaced during the wear process and formed a thin mechanically mixed tribo layer and reduced the friction. The thin mechanically mixed tribo layer at the interface restricted the direct contact of asperities in the mating surface and reduced the wear loss. Adhesive wear was found to be active in the composites with Sn metal powder.