The extraordinary ability of shape-memory alloys to recover after large imposed deformation motivates efforts to transpose these properties onto ceramics, which would enable practical shape-memory properties at high temperatures and in harsh environments. The theory of mechanical compatibility was utilized to predict promising ceramic candidates in the system (Y0.5Ta0.5O2)1-x-(Zr0.5Hf0.5O2)x, 0.6<x<0.85. When these compatibility conditions are met, a reduction in thermal hysteresis by a factor of 2.5, a tripling of deformability, and a 75% enhancement in strain recovery within the shape-memory effect was found. These findings reveal that predicting and optimizing the chemical composition of ceramics to attain improved crystallographic compatibility is a powerful tool for enabling and enhancing their deformability that could ultimately lead to a highly reversible oxide ceramic shape-memory material.
Bibliographical noteFunding Information:
E.Q. and J.J. acknowledge support by the German Research Foundation (DFG) via a Reinhart Koselleck project Grant No. 313454214. J.R.G. gratefully acknowledges the financial support of the Stanback Space Innovation Program at Caltech and from the U.S. Department of Energy's Basic Energy Sciences through Grant No. DESC0016945. We also acknowledge H. Vo and P. Hosemann for providing their instrument for preliminary nanomechanical investigations. The work from the University of Minnesota was supported by NSF (Grant No. DMREF-1629026), ONR (Grant No. N00014-18-1-2766), and the MURI program (Grants No. FA9550-18-1-0095 and No. FA9550-16-1-0566). H.G. and R.D.J. are also pleased to acknowledge the support of Medtronic Corp, the Institute on the Environment (RDF fund), and the Norwegian Centennial Chair Program. X.C. thanks the financial support of the HK Research Grants Council under Grants No. 26200316 and No. 16207017. X.C. also thanks the Isaac Newton Institute for Mathematical Sciences for support and hospitality during the program “The Mathematical Design of New Materials” when work on this paper was undertaken by EPSRC Grant No. EP/R014604/1.