Fostering crack deviation via local internal stresses in Al/NiTi composites and its correlation with fracture toughness

In the framework of metal matrix composites, a research gap exists regarding tailoring damage mechanisms. Thepresent work aims at developing an Al/NiTi composite incorporating internal stresses in the vicinity of re-inforcements. The composite is manufactured by friction stir processing which allows a homogenous NiTi dis-tribution and a good Al/NiTi interface bonding. The internal stresses are introduced via shape memory effect ofthe embedded NiTi particles. The induced internal strainfield is confirmed by digital image correlation and thecorresponding stressfield is evaluated byfinite element simulation. It is found that the damage mechanism ismodified in the presence of internal stresses. The consequent enhancement of fracture toughness arises by thefact that the internal stresses foster discrete damages shifted from the fracture ligament line. These damagesrelease the stress concentration at the main crack tip and lead to a deviated crack path when coalescing to accommodate fracture propagation.

Publication year:2019

BOF-keylabel:yes

IOF-keylabel:yes

BOF-publication weight:10

CSS-citation score:1

Authors from:Higher Education

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