The evaluation of microstructure, grain boundary character and micro texture of [Al/Si₃N₄/Al₂O₃] P nanocomposites fabricated through PM route and its influence on compressive and three-body wear properties

Abstract

The compressive properties and 3 body wear characteristics of powder metallurgical (PM) processed [Al/Si3N4/Al2O3] P Nanocomposites with single and combined reinforcement of Al2O3 and Si3N4 reinforcing particles having different compositions (1%, 2% and 3%) were studied and evolution of microstructure, grain boundary character and micro texture of fabricated [Al/Si3N4/Al2O3] P Nanocomposites was investigated through EBSD in the present research work. The fraction of high angle boundaries (HAGBs) were observed more in combined reinforcing samples of Al2O3 and Si3N4 whereas a single reinforcing sample of Al2O3 and Si3N4 showed fewer HAGBs. Micro texture results showed the strong textures components near to {112}<111> Cu and {110}<111 for pure sintered Al sample P and mixed reinforcement composites (M1, M2 and M3) > P whereas for single reinforcing sample showed weak textures near to transverse direction. Out of all fabricated composites, 2 % mixed Al2O3 and Si3N4 reinforced composite revealed the maximum ultimate compressive strength (209.98 MPa) and least wear rate (0.1 mm3/min mm3/N-cm for 1 kg load and 3.5 mm3/N-cm for 2kg load) attributing formation of nanocluster causing grain boundary pinning effect. The dominant failure mechanism for all samples was also detected and found to be a mixed-mode ductile failure mechanism for 2 % mixed Al2O3 and Si3N4 reinforcement composite while other sample failed through ductile as well as mixed-mode mechanisms.