Effect of Fe Addition on Microstructure and Mechanical Properties of As-cast Ti49Ni51 Alloy

Abstract

Effect of Fe addition on microstructure and mechanical properties of as-cast Ti49Ni51 alloy were investigated. The experimental results shows the microstructures of Ti48.5Ni51Fe0.5 and Ti48Ni51Fe1 alloys are mainly composed of TiNi matrix phase (body-centered cubic, BCC), Ti3Ni4 and Ni2.67Ti1.33 phases; the microstructure of Ti47Ni51Fe2 alloy is mainly composed of BCC TiNi, Ti3Ni4, Ni2.67Ti1.33, and Ni3Ti phases; the microstructure of the Ti45Ni51Fe4 alloy is mainly composed of TiNi, Ti3Ni4 and Ni3Ti phases. The Ni3Ti nanocrystalline precipitates at the adjacent position of Ni2.67Ti1.33 phase. The Ti48.5Ni51Fe0.5 and Ti48Ni51Fe1 alloys have high yield strength and fracture strength, and can be as the engineering materials with excellent mechanical properties. In addition, the Ti48.5Ni51Fe0.5 alloy with the low elastic modulus and large elastic energy is also a good biomedical alloy of hard tissue implants. The fracture mechanism of the four alloys is mainly cleavage fracture or quasi-cleavage fracture, supplemented by ductile fracture. The experimental data obtained provide the valuable references in application of as-cast alloys and heat-treated samples in the future.

Tuning the temperature range of superelastic Ni-Ti alloys for elastocaloric cooling via thermal processing

“…The µXRD results indicated that the Ni-Ti specimens possessed a polycrystalline texture with submicron grains. The XRD patterns showed that the homogenized sample was composed of a single phase of Ni-Ti matrix, and the other samples consisted of the Ni-Ti matrix and additional Ni-rich intermetallic phases, such as Ni 4 Ti 3, Ni 3 Ti 2, and Ni 3 Ti, which are consistent with previous literature [8,28,29]. As the duration of low-temperature aging is increased, Ni 4 Ti 3 phase was formed in the 10 min-aged samples, and Ni 3 Ti 2 and Ni 3 Ti phases were formed in the sample aged for over…”

“…It has been reported that precipitation hardening caused by the precipitation of Ni 4 Ti 3 produced by the age-hardening treatment contributes to the improvement of superelasticity by making the alloy less susceptible to slip [28]. These results revealed that it is important to control the microstructures and transformation temperatures to enhance superelasticity.…”

The Effect of Annealing Treatment on the Microstructure and Texture of a Cold-Rolled TiNiFe Shape Memory Alloy Tube

“…An intermetallic compound can be formed because of the addition of Fe elements by replacing Ni atoms, resulting in a lattice distortion and atomic relaxation [19,20]. TiNiFe SMAs have good SMEs and mechanical properties and a relatively low martensitic transformation temperature [21], so they are also widely used in aerospace and other fields.…”

Study on the Mechanical Properties of Ni-Ti-Cu Shape Memory Alloy Considering Different Cu Contents

“…At present, there are three categories of the SMA that have been put into application [1], the Ni based, the Copper based and the stainless steel based. The Nibased SMA, especially the NiTi SMA shows excellent properties such as Shape Memory Effect and superelastic [2,3], damping characteristics [4,5], corrosion resistance [6][7][8] and biocompatibility [9,10]. Based on these characteristics, Ni-based SMA has been widely used in aerospace, machinery, chemical, electronics and medical fields [11][12][13].…”