Strengthening contributions in ultra-high strength cryorolled Al-4%Cu-3%TiB2 in situ composite
(Advanced Materials Processing Laboratory, Department of Metallurgical and Materials Engineering,
National Institute of Technology, Tiruchirappalli, Tamil Nadu 620015, India)
National Institute of Technology, Tiruchirappalli, Tamil Nadu 620015, India)
Abstract: Ultra-high strength Al alloy system was developed by cryorolling and the contribution of various strengthening mechanisms to the overall yield strength of the system was evaluated. Cryorolling of Al-4%Cu-3%TiB2 in situ composite followed by short annealing at 175 °C and ageing at 125 °C resulted in an ultra-high yield strength of about 800 MPa with 9% total elongation. The strengthening contributions form solid solution strengthening, grain refinement, dislocation strengthening, precipitation hardening and dispersion strengthening were evaluated using standard equations. It was estimated that the maximum contribution was from grain refinement due to cryorolling followed by precipitation and dispersion strengthening.
Key words: Al alloy; cryorolling; metal matrix composites; ultrafine grained microstructure; strengthening mechanisms