نوع مقاله : علمی و پژوهشی
عنوان مقاله English
نویسندگان English
This study investigates the impact of the sequence of high-pressure torsion (HPT) processes and subsequent aging on the microstructure and mechanical properties of aluminum alloy 7075. Samples of Al7075 underwent heat treatment and mechanical processing under two different conditions: solid solution-aging-high-pressure torsion (SAH) and solid solution-high-pressure torsion-aging (SHA). The microstructural changes, including grain size and precipitate characteristics, were analyzed through optical microscopy and both scanning and transmission electron microscopies. Phase identification was conducted using X-ray diffraction (XRD), while hardness and uniaxial tensile tests were performed to evaluate mechanical behavior variations. The findings revealed that the grain size for SHA samples was smaller (65±3 nm) compared to SAH samples (78±3 nm). Furthermore, the distribution of precipitates (MgZn2) in SHA samples was more homogeneous than in SAH samples, leading to enhanced hardness and strength in the SHA samples. The ultimate tensile strength reached 740±10 MPa for SHA samples, whereas SAH samples achieved approximately 670±10 MPa. Overall, high-pressure torsion contributed to a significantly finer microstructure, increasing the preferred sites for precipitate formation during aging, which in turn resulted in improved hardness and strength due to more uniform precipitate distribution.
کلیدواژهها English
