The Effects of Precipitate Size on the Hardness and Wear Behaviors of Aged 7075 Aluminum Alloys Produced by Powder Metallurgy Route

摘要

In this study, the effects of precipitate size, which occurred on the microstructure by applying T6 heat treatment at different temperatures and different time intervals, were investigated on hardness and wear behaviors of 7075 Aluminum alloys produced by powder metallurgy route. Aging heat treatments were performed at three different temperatures (110-130 °C) and four different times (16-28 h). The results show that MgZn_2 precipitates were formed in the microstructure by aging heat treatments and their sizes were changed depending on aging temperature and time. The precipitate size was increased by increasing aging temperature and time. The largest size of the precipitate was measured from SEM images of the samples aged at 130 °C for 24 h. The highest hardness values were measured at 120 °C for 24-h aged samples. The wear test results revealed that the weight loss was increased with increase in sliding distance and the minimum weight loss was observed at 120 °C for 24-h aged samples.