Correlation between microstructures and mechanical properties in Ni-rich Ni–Mn–Ga high-temperature shape-memory alloys. Issue 6 (13th April 2018)

• Record Type: Journal Article
• Authors: Hou, Long; Tong, Hui; Dai, Yanchao; Fautrelle, Yves; Moreau, Rene; Ren, Zhongming; Li, Xi
• Is Part Of: Materials science and technology. Volume 34:Issue 6(2018)
• Page Start: 712
• Page End: 717
• Publication Date: 2018-04-13
• Subjects: Ni–Mn–Ga alloy -- high-temperature shape-memory alloy -- microstructure -- mechanical property; Materials science -- Periodicals; Microstructure -- Periodicals; Metallurgy -- Periodicals; 620.1105
• DOI: 10.1080/02670836.2017.1410928
• Languages: English
• ISSNs: 0267-0836

Abstract

ABSTRACT: Microstructures and mechanical properties of polycrystalline and single-crystalline Ni55+ x Mn25 Ga20− x ( x = 1, 2, 3) alloys are investigated. The alloys exhibit a single martensite phase for x = 1, and two phases containing tetragonal martensite phase and face-centered γ phase for x = 2 and 3. The appearance of γ phase can apparently raise the strength and plasticity of the alloys. Moreover, single crystals show better mechanical properties compared with the polycrystals with the same composition. Furthermore, a kind of net-like γ phase is observed in directionally solidified Ni58 Mn25 Ga17 single crystal. This alloy exhibits excellent plasticity due to that the crack propagation is seriously hindered by the plastic net-like γ phase.