The effect of temperature and strain rate on elongation to failure in nanostructured Al-0.2wt% Zr alloy fabricated by ARB process

A nano/ultra-fine grain Al-0.2wt% Zr alloy was produced by accumulated roll bonding (ARB) process after 10 cycles. The fraction of high angle grain boundaries increased from 8% to 65.4% during 10 passes during ARB process. This alloy was subjected to tensile test at different temperatures (523,573 and 623 K) and strain rates (0.1 and 0.01 s-1). The optimum condition of temperature and strain rate of 623k and 0.01s-1 was achieved for maximum elongation to failure, leading to 100% elongation, although maximum elongation was achieved at higher strain rate and maximum chosen temperature. In fracture surfaces after the test, dimples in higher temperature were deeper, bigger, and longer than low temperature. Because of presenting the superplasticity character at elevated temperature and higher strain rate, there was no evidence of necking after failure.