Temperature effects on the dry sliding wear of Al2O3f/SiCp/Al MMCs with different fiber orientations and hybrid ratios

Abstract

Al 2 O 3 fiber (Al 2 O 3f ) and SiC particle (SiC p ) hybrid metal matrix composites (MMCs) were manufactured in a squeeze casting method and investigated for their mechanical and wear properties at elevated temperatures of 100 °C and 150 °C. The pin specimens had different ratios of fiber to particle content but their total weight fraction was constant at 20 wt.%. Dry sliding wear tests were conducted with a pin-on-disk friction and wear tester. The morphologies of the worn surfaces were examined using a scanning electron microscope (SEM) to observe the wear characteristics and investigate the wear mechanism. An optical microscope (OM) was used to examine the precipitations of the MMCs after wear tests under different temperatures. The grown precipitations improved the hardness of the matrix material during the wear tests at 150 °C. Thus, the wear resistance was enhanced at 150 °C due to the precipitation strengthening of the FeSiAl 5 . Furthermore, the tests results revealed that the wear resistance of normal (N) MMCs was superior to that of planer random (PR) MMCs as the PR-fibers were easily pulled out whole from the worn surface. The results of this investigation showed that the wear resistance of dry sliding wear decreased as the SiC p content and increased at 100 °C and 150 °C, independently of the fiber orientation.