Compressive deformation behaviour of Al alloy (2014)-10 wt.% SiC_p composite:Effects of strain rates and temperatures

摘要

This paper deals with the compressive deformation behaviour of AA2014-10 wt.% SiC_p composites synthesized by stir casting technique. The response of the composites was studied over the strain rates of 0.01 -10/s and the temperature range of 200-500 ℃. The flow stress increased with increasing strain rates while increasing temperature produced a reserve effect. The flow behaviour of the samples has been represented by Zener-Holloman parameter Z that was affected by strain rate and temperature in a manner similar to that of the flow stress. The lowering of Z value with increasing temperature is essentially due to extensive dynamic softening. The stress exponent (n) and deformation activation energy (Q) have been evaluated by linear regression analysis. The activation energy for the hot deformation of the composite was found to be 168 kJ/mol, which is higher than bulk self diffusion of pure Al i.e., 142 kJ/mol. The higher activation energy required for the flow of composite was mainly due to the alloying elements present in the Al matrix and dispersion of SiC particles that restricted the flow of material.