An investigation on the properties of boron modified Cu-Al-Be polycrystalline shape memory alloys

摘要

Effect of microalloying of boron (B) i.e., 0.02-0.15 wt% and the variation of composition of Al and Be from 11.3 to 11.9 wt% and 0.41-0.44 wt% respectively, has been investigated on the grain refinement and shape memory properties of polycrystalline Cu-Al-Be shape memory alloy. The tests have been carried out for microstructure, morphology, phases, crystal structure, phase transformation temperatures and shape recovery ratio. The investigation results in boron has strong impact on grain refinement with minimal addition, followed by Al and Be. AlB2 acts as heterogeneous nucleation site in grain refinement and it increases with increase in B and Al. Transformation temperatures increases with boron up to 0.08 wt% and then decreases, whereas increase in Al and Be decreases the temperatures. Doping and increasing of boron up to 0.15 wt% exhibits complete shape recovery, whereas Be < 0.42 wt% and Al < 11.8 wt% exhibits poor recovery ratio. (C) 2020 Elsevier B.V. All rights reserved.