Hardness and dry sliding wear behavior of SiC reinforced Al 7150 alloy composite synthesized under the influence of aging, varying compaction pressures, particle size and volume fraction of ceramic particulates by hot compaction technique

Abstract

The objective of the current investigation is to study the hardness and dry sliding wear behavior of SiC reinforced Al 7150 alloy composite synthesized under the influence of aging, varying compaction pressures, particle size and volume fraction of ceramic particulates by hot uni-axial compaction route. The varying vol% (0, 5, 10 and 15%) of coarse (45 μm) and nano SiC particulates (80 and 27 nm) were blended with the base Al 7150 alloy powders in a planetary ball mill to produce five sets of Al 7150 alloy composite samples via hot uni-axial compaction technique, under different compaction pressures of 400, 450, 500, 550 and 600 MPa. The hot compaction temperature was maintained at 450 °C with varying compaction durations of 30, 45 and 60 min before ejection. The VHN tests showed that the samples synthesized by applying a compaction pressure of 550 MPa produced better microhardness values than the other set of specimens. The hot compacted samples produced by applying a compaction pressure of 550 MPa, were first solutionized followed by artificial aging at 115 °C for durations of 3, 6, 12, 24, 30, 45, 60 and 96 h. The artificially aged samples were tested for VHN hardness and wear resistance using a pin on disc wear tester. The results revealed that the hardness and wear behavior of the samples were influenced not only by the addition of varying volume fraction and particle size of SiC particulates but also due to the occurrence of precipitation hardening. The test samples were characterized using XRD, FESEM and EDS to determine the mechanism of wear.