Interstitial-oxygen-induced γ-phase precipitation and martensitic transformation behavior in Ni–Mn–Sn–Co alloy prepared through binder jetting and sintering

• Published in: Journal of materials science & technology Vol. 214; pp. 272 - 277
• Main Authors: Zhong, Shijiang, Qian, Mingfang, Shen, Xinxin, Gong, Shuhe, Sun, Liangbo, Shen, Ping, Zhang, Xuexi, Geng, Lin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 10.04.2025
• Subjects: Additive manufacturing (AM); Binder jetting (BJ); Magnetic shape memory alloys (MSMAs); Martensitic transformation (MT) behavior; Sintering; Additive manufacturing (AM); Magnetic shape memory alloys (MSMAs); Martensitic transformation (MT) behavior; Binder jetting (BJ); Sintering
• ISSN: 1005-0302
• DOI: 10.1016/j.jmst.2024.07.011

•Effect of residues in binder-jetted and sintered Ni–Mn–Sn–Co alloys was studied.•Mechanism underlying interstitial-oxygen-induced γ-phase precipitation was clarified.•Effect of γ phase on martensitic transformation behavior of Ni–Mn–Sn–Co alloys was discussed. Binder jetting has shown promise for the rapid preparation of brittle Ni–Mn-based alloy parts, while the effect of residues on martensitic transformation (MT) behavior has rarely been studied. Here, binder-jetted and sintered Ni–Mn–Sn–Co alloys with different residue content were prepared. In a 2 h sintered alloy, interstitial-oxygen-induced γ-phase precipitation was found. Owing to its intrinsic hardness and lattice mismatch with the matrix, the γ phase hindered the movement of MT fronts, and internal stress fields developed in the matrix, which increased the hysteresis and MT width, and decreased the MT temperature. In a 16 h sintered alloy, at a low residual oxygen content, the γ phase dissolved in the matrix, rejuvenating MT behavior. This work improves our understanding regarding the effect of residues on the properties of Ni–Mn–Sn–Co alloys produced through binder-based additive manufacturing, and proposes a strategy for regulating the MT behavior of such alloys. [Display omitted]