Influence of Doping Tb on the Mechanical Properties and Martensitic Transformation of Ni-Mn-Sn Magnetic Shape Memory Alloys

Abstract

Brittleness and low working temperature are two key factors that restrict the application of Ni-Mn-Sn alloys. Element doping is an effective means to improve performance of materials. In present paper, martensitic transformation (MT) and mechanical properties of Ni 48 Mn 39 Sn 13−x Tb x (x = 0, 0.5, 1, 2, and 5 at.%) alloys are investigated. It is found that the Tb addition refines significantly the grains and causes the formation of a Tb-rich phase. All the samples undergo the martensitic transformation from parent phase to martensite. And the martensitic transformation characteristic temperatures increase remarkably from −60.7 • C for x = 0 to 364.1 • C for x = 5. The appropriate amount of Tb addition in Ni 48 Mn 39 Sn 13−x Tb x (x = 0, 0.5, 1, 2, and 5 at.%) alloys significantly enhances the compressive strength and improves the ductility, which can be ascribed to the grain refinement. The compressive stress of 571.8 MPa and strain 22.0% are obtained in the Ni 48 Mn 39 Sn 11 Tb 2 alloy. Then the mechanical properties decrease with the further increased Tb content. Simultaneous improving of martensitic transformation temperature and mechanical properties in Ni-Mn-Sn magnetic alloy are achieved by Tb doping.

Tunable Martensitic Transformation and Magnetic Properties of Sm-Doped NiMnSn Ferromagnetic Shape Memory Alloys

“…It is agreed that the substitution with atoms having different sizes from their parent atoms results in the expansion or contraction of the unit cell, and hence lattice distortion. Figure 2b shows that as the e/a is increased, the characteristic temperatures of martensitic transformation increase linearly, which is in accordance with previous reports [32].…”

“…Unfortunately, the highly brittle nature and poor mechanical properties of NiMnSn alloys are major drawbacks. Additionally, NiMnSn alloys show a low working temperature due to coupling between MT and ferromagnetic transition [32].…”

Multi-Physics Bi-Functional Intelligent Meta-Device Based on the Shape Memory Alloys

“…Although all these works try to fabricate metamaterials that can be applicable in multiple physical fields, a design of a meta-device that can not only work in multi-physical domains but also can automatically switch from one function to another as the environmental parameter changes, has still not been proposed. In this article, we try to solve the problem and provide a method to build such an intelligent bi-functional meta-device that can work in both thermal conduction and DC electric conduction situations by utilizing the shape memory alloys (SMAs) [29][30][31]. Due to its special lattice structure, owing to the solid-solid transition, the shape memory alloy (SMA) will switch from its original figure to a deformed figure as it is heated or cooled.…”

Magneto-Structural Transition and Refrigeration Property in All-D-Metal Heusler Alloys: A Critical Review

“…A variety of approaches have been employed to improve the mechanical properties of Heusler alloys [7,8,[26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. In 2015, Wei et al [41] prepared a kind of novel Heusler alloys by replacing p-group atoms with third transition metal atoms.…”