Thermo-mechanical and crack position on stress intensity factor in particle-reinforced Zinc-aluminium alloy composites

Alumina (Al2O2) filled Zinc-aluminium (ZA-27) alloy matrix composites are fabricated by stir casting techniques with varying alumina weight percentages (0 wt.%, 4 wt.%, 8 wt.% and 12 wt.% of Al2O3) and evaluated the physical and mechanical properties, thermal and thermo-mechanical behaviour of these composites. In this study, thermal conductivity of the unfilled ZA-27 alloy composite is evaluated in finite element analysis (FEA) method and showed almost similar results with the Hasselman and Johnson (H&JM) model results along the transverse direction. However, FEA and H&JM model results are slightly higher than the experimental results (approximately same i.e. 135 +/- 1 W/m-K). Whereas, in longitudinal direction the error associated between experimental - Hamilton and Crosser model (H&CM) and experimental-FE simulation for 4 wt.% alumina reinforcement is 1.6%, 1.66%, while for 8 wt.% reinforcement it is 0.92%, 0.98% and for 12 wt.% reinforcement it is 5.5%, 2.22%, respectively. The thermo-mechanical characteristics such as storage modulus, loss modulus and damping properties as viscoelastic responses of the composites are investigated in the temperature range of 80-400 degrees C. At lower temperature regime the trend of storage modulus remained in the order E-0wt:%' > E-12wt:%' > E-4wt:%' > E-8wt:%' of the composites. However, at higher temperature range (i.e. 175-375 degrees C) the composite with 4 wt.% and 8 wt.% exhibited same E' value in magnitude. At the end, the stress intensity factors of all the composites are studied in experimentally and FEM technique. The results are obtained from this analysis help to understand the de-bonding phenomenon between particulate and matrix interface. (C) 2011 Elsevier B. V. All rights reserved.