Effect of Al-5Ti-1B master alloy and heat treatment conditions on the mechanical properties and dry sliding wear behavior of an Al–Zn–Mg–Cu aluminum alloy produced by SIMA process

Abstract

In this study, the effect of Al–5Ti–1B grain refiners and modified SIMA process on an Al–Zn–Mg–Cu alloy was studied. The optimum level of Ti was found to be 0.1wt.%. The specimens subjected to deformation ratio of 40% (at 300°C) and various heat treatment times (10–40min) and temperature (550–600°C) regimes were characterized in this study. Reheating condition to obtain a fine globular microstructure was optimized. Microstructural examinations were conducted by optical and scanning electron microscopy coupled with an energy dispersive spectrometry. The optimum temperature and time in SIMA process are 575°C and 20min, respectively. T6 heat treatment including quenching to room temperature and aging at 120°C for 24h was employed to reach to the maximum strength. Significant improvements in mechanical properties were obtained with the addition of grain refiner combined with T6 heat treatment. After the T6 heat treatment, the average tensile strength increased from 283MPa to 587 and 252MPa to 564 for samples refined with 2wt.% Al–5Ti–1B before and after SIMA process, respectively. The results showed that ultimate strength of globular microstructure specimens was a lower value than that of Ti-refined specimens without SIMA process.