Hybrid Aluminium Metal Matrix Composite Reinforced with SiC and TiB2

Abstract

In this research work an effort has been made to prepare hybrid aluminium metal matrix composite to study its machining and mechanical properties. Preparation of hybrid aluminium metal matrix composite is made by reinforcing Silicon carbide and Titanium di boride. Morphology of the composite and reinforced particle distribution were studied in detail by optical microscopy. The hardness test has been carried out to determine the hardness of the cast composite using Vickers hardness testing instrument. The hardness test shows addition of reinforcement SiC and TiB2 increases hardness value. But increase in reinforcement up to 15wt % reveals reduction in hardness value. Mechanical testing was carried out on the tensile samples prepared from the cast composite specimen of different compositions. From tensile test results it has been observed that addition of reinforcement SiC to base metal added 20% strength to the composite but addition of TiB2 reduction in 50 - 60% strength is recorded. Wear test analysis has been carried out to study the wear resistance behaviour of TiB2. Wear test analysis proved that the addition of TiB2 increased the wear resistance behaviour of composite. The cast composite specimens were carefully machined. The effect of machining parameters like cutting speed (s), feed rate (f), depth of cut (d) and weight percentage of TiB2 on surface roughness (Ra) were investigated during turning operation. The analysis of variance method shows that % of TiB2 reinforcement is the most influential parameter which affects surface quality and its contribution is 38.86%. Tool wear analysis was carried out to study tool wear pattern, built-up edge formation, influence of TiB2 on tool wear and how these factors affects surface quality of cast composite. Analysis proves TiB2 cause high tool wear, poor surface finish and built-up edge formation affects surface quality.