Microstructure-property evolution of mechanically alloyed Al-20 wt% Si matrix powders and sintered composites reinforced withTiB2 particulates

Gökçe H., Öveçoğlu M. L.

Engineering Science and Technology, an International Journal, vol.39, 2023 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 39
  • Publication Date: 2023
  • Doi Number: 10.1016/j.jestch.2023.101341
  • Journal Name: Engineering Science and Technology, an International Journal
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, INSPEC, Directory of Open Access Journals
  • Keywords: Mechanical properties, Metal-matrix composites (MMCs), Microstructural analysis, Powder processing, Si solubility in α-Al matrix, Sub-micron grains
  • Istanbul Technical University Affiliated: Yes


© 2023Microstructural, physical and mechanical properties of Al–20 wt% Si matrix alloy powders and those reinforced with TiB2 and their sintered composites were investigated in relation to TiB2 content and mechanical alloying (MA) durations. Al–20 wt% Si matrix alloy powders and those containing 5 and 10 wt% TiB2 reinforcing particles were MA'd for 1, 2, 4, and 8 h followed by consolidation and sintering at 843 K. Si solubility in a-Al matrix increased with increasing MA duration. Increasing the TiB2 content, on the other hand, resulted in a systematic drop in Si solubility over the same MA period. Scanning electron micrographs of the sintered samples revealed sub-micron-sized, rod-shaped Si and spherical Al9Si phase particles. With increasing TiB2 content and MA durations, the microhardness of the Al20Si/TiB2 composites improved. The wear resistances of TiB2 reinforced composites better by 5 to 8 times than that of the as-blended and 1 h MA'd AlSi matrix alloy. Due to the presence of the Al3Ti intermetallic phase, sintered composite samples containing 10 wt% TiB2 particles MA'd for 8 h had the maximum hardness value and lower wear resistance values than those of the Al–20 wt% Si/5 wt% TiB2 composites.