Microstructure evolution and flow behavior of hot-rolled aluminum – 5% B4C composite

• Published in: Materials in engineering 2014-01, Vol.53, p.581-587
• Main Authors: Gangolu, S., Rao, A.G., Prabhu, N., Deshmukh, V.P., Kashyap, B.P.
• Format: Article
• Language: English
• ISSN: 0261-3069
• DOI: 10.1016/j.matdes.2013.07.025

•Anisotropy in rolled composite was studied as a function of temperature.•Change in strengthening of composite with sample orientation (L &T).•EBSD used for exploring microstructure variation in Al–5% B4C composite. Differential strain rate compression tests were conducted to study flow behavior of hot rolled Al–5wt% B4C composite as a function of sample orientation (longitudinal and transverse) over the temperature and strain rate ranges of 25–500°C and 10−4 to 1s−1, respectively. The longitudinal samples are found to show lower flow stress than that shown by the transverse samples in the temperature range of 25–200°C. The reverse becomes true at higher temperatures of 300–500°C. The values of stress exponent (n) and activation energy for deformation (Q), based on applied stress, ranged from 10 to 46 and 307–416kJ/mol, respectively. However, by considering effective stress, these values were reduced to n=8 and Q=126–190kJ/mol. This stress exponent ofn=8 is further reduced to n=5 by considering substructural evolution, which suggests the dislocation climb creep mechanism to be favorable for deformation.