Composites Part B-engineering | 2021
Unprecedented enhancement in strength-plasticity synergy of (TiC+Al6MoTi+Mo)/Al cermet by multiple length-scale microstructure stimulated synergistic deformation
Abstract
Abstract Metal-ceramic composites generally exhibit limited strength-plasticity synergy due to pronounced difference in elastic and plastic deformation between “soft phase” and “hard phase”, bottlenecking their applications. This work proposes a novel microstructure design concept using refractory metals and intermetallics to offer compromises between “soft phase” and “hard phase”. A cost-effective fabrication method was used to produce 70\xa0vol% (TiC\xa0+\xa0Al6MoTi\xa0+\xa0Mo)/Al cermet. The cermet is composed of submicron-TiC, micron-Al6MoTi and nano-Mo particles separated by Al in homogeneous microstructure. This multiple length-scale microstructure could delocalize stress concentration, enhance work hardening and deformation compatibility in cermet, resulting in unprecedentedly enhanced strength-plasticity synergy. Ultimate compressive strength, plastic strain and product of strength and plasticity of (TiC\xa0+\xa0Al6MoTi\xa0+\xa0Mo)/Al at room temperature and 573\xa0K respectively are 1227\xa0MPa, 6.9%, 7445\xa0MPa·% and 781\xa0MPa, 15.0%, 10021\xa0MPa·%, which are increased by ~30%, ~25%, ~60% and ~37%, ~9%, 41% respectively compared with those for traditional 70\xa0vol% TiC/Al. This work opens new perspectives for the design and application of metal-ceramic composites with high strength and plasticity synergy.