Aerospace Engineering, Materials Science and Engineering, Mechanical Engineering, Ames Laboratory
Journal or Book Title
Elastocaloric cooling, a solid-state cooling technology, exploits the latent heat released and absorbed by stress-induced phase transformations. Hysteresis associated with transformation, however, is detrimental to efficient energy conversion and functional durability. We have created thermodynamically efficient, low-hysteresis elastocaloric cooling materials by means of additive manufacturing of nickel-titanium. The use of a localized molten environment and near-eutectic mixing of elemental powders has led to the formation of nanocomposite microstructures composed of a nickel-rich intermetallic compound interspersed among a binary alloy matrix. The microstructure allowed extremely small hysteresis in quasi-linear stress-strain behaviors—enhancing the materials efficiency by a factor of four to seven—and repeatable elastocaloric performance over 1 million cycles. Implementing additive manufacturing to elastocaloric cooling materials enables distinct microstructure control of high-performance metallic refrigerants with long fatigue life.
Hou, Huilong; Simsek, Emrah; Ma, Tao; Johnson, Nathan S.; Qian, Suxin; Cissé, Cheikh; Stasak, Drew; Al Hasan, Naila; Zhou, Lin; Hwang, Yunho; Radermacher, Reinhard; Levitas, Valery I.; Kramer, Matthew J.; Zaeem, Mohsen Asle; Stebner, Aaron P.; Ott, Ryan T.; Cui, Jun; and Takeuchi, Ichiro, "Fatigue-resistant high-performance elastocaloric materials made by additive manufacturing" (2019). Aerospace Engineering Publications. 150.