2nd International Advances in Applied Physics & Materials Science- APMAS2012, Turkey, 1 - 04 April 2012, pp.163
Al-wt.%13.6Cu-wt.%6Si alloy samples (diameter: 4 mm, length 200 mm) were prepared under vacuum atmosphere. The samples were directionally solidified upward at a constant growth rate (V=17.40 μm/s) in a wide range of temperature gradients (G=1.6–6.12 K/mm) and a constant temperature gradient (G=4.64 K/mm) with different growth rates (V=8,30–166.0 μm/s) using by Bridgman type directional solidification apparatus. The values of dendritic spacings (l and?l2) were measured from longitudinal and transverse sections of the samples. The dependency of microstructures on the G and V were determined with linear regression analysis and experimental equations were found as l?=24.66xG-0.50, l?=662.22xV-0.21, l2=4.00xG-0.42, l2=91.83xV-0.31. The measurements of microhardness of directionally solidified samples were obtained by using a microhardness test device. The dependence of microhardness HV on temperature gradient and growth rate were analyzed. The dependency of microhardness on the G and V were also determined with linear regression analysis as HV=57.28 G0.11 HV=83.18 V0.05. The experimental results show that the microhardness (HV) of the directionally solidified Al-Cu-Si alloy increases with increasing the growth rate. The results obtained in this work were compared with the previous similar experimental results.