Statistical Analysis of Fracture Strength Using Weibull Distribution in Aluminum-Alumina (Al2O3) Particulate Composites

The mechanics of composite materials and their fracture behaviors are really complex. The reason for this is inconsistent process stability and reliability, combined with production and processing problems. In this work, an attempt has been made to statistically analyse the tensile behavior of metal matrix composite. Composite of Aluminium alloy containing 5 to 20 % volume fraction of Al₂O₃ particles of 15 μm size was prepared by adding alumina particles to a vigorously agitated semi solid Aluminum alloy. Prior to this, alumina particles were subjected to preheating at 800°C for 5hrs. Particles were added to the Aluminium alloy heated to 850°C by using a mixer in the nitrogen medium. Twenty tension tests were performed for each volume fraction according to ASTM standards B557 (American Society of Testing Materials standards) and using the test data, the corresponding weibull distribution was obtained. The reliability of the composite characteristics in terms of its tensile strength was assessed. An important implication of the present study is that the weibull distribution describes more appropriately, the experimentally measured strength data.