scholarly journals Deformational Treatment Of Shape Memory Alloy Ti–ni, Produced By Electron Beam Melting Method

2015 ◽  
Vol 2015 (1) ◽  
pp. 18-20
Author(s):  
A.Yu. Severin ◽  
◽  
V.A. Berezos ◽  
A.N. Pikulin ◽  
◽  
...  
2004 ◽  
Vol 7 (2) ◽  
pp. 263-267 ◽  
Author(s):  
Jorge Otubo ◽  
Odair Doná Rigo ◽  
Carlos de Moura Neto ◽  
Michael Joseph Kaufman ◽  
Paulo Roberto Mei

Author(s):  
Hao Sun ◽  
Jianjun Luo ◽  
Ming Lu ◽  
Dmytro Nykypanchuk ◽  
Yong Shi

In order to create shape memory alloy (SMA) bimorph microactuators with high-precision features, a novel fabrication process combined with electron beam (E-beam) evaporation, lift-off resist and isotropic XeF2 dry etching method was developed. To examine the effect of E-beam deposition and annealing process on nitinol (NiTi) characteristics, the NiTi thin film samples with different deposition rate and overflow conditions during annealing process were investigated. With the characterizations using scanning electron microscope and x-ray diffraction, the results indicated that low E-beam deposition rate and argon employed annealing process could benefit the formation of NiTi crystalline structure. Besides, SMA bimorph microactuators with high-precision features as small as 5 microns were successfully fabricated. Furthermore, the thermomechanical performance was experimentally verified and compared with finite element analysis simulation results.


2018 ◽  
Vol 770 ◽  
pp. 148-154 ◽  
Author(s):  
Muhammad Dilawer Hayat ◽  
Gang Chen ◽  
Nan Liu ◽  
Shifaz Khan ◽  
Hui Ping Tang ◽  
...  

NiTi is characterized as a shape memory alloy that has found interesting applications from aerospace to biomedical engineering. The use of NiTi in biomedical applications is due to its excellent biocompatibility, shape memory and pseudoelastic properties. These properties make NiTi an excellent candidate for many functional designs in biomedical fields. However, difficulties in manufacturing and processing of this alloy are significant hindrance to widespread applications. Advances in additive manufacturing (AM) such as selective laser and electron beam techniques have provided opportunities in manufacturing complex shaped NiTi parts. In this research paper, we demonstrate manufacturing of NiTi parts using a selective electron beam melting (SEBM) technique. Complete evaluation of physical, chemical and mechanical properties was carried out to determine the suitability of SEBM process. Differential scanning calorimeter (DSC), X-ray diffraction (XRD), and metallographic analyses were employed for the thermal and structural characterizations. The obtained results suggest that it is imperative to, and challenging to control the additive manufacturing process in order to obtain the desired microstructures and avoid unwanted texture. An exhaustive heat treatment of the samples after SEBM process might also be necessary.


2017 ◽  
Vol 10 (04) ◽  
pp. 1750043 ◽  
Author(s):  
P. Krooß ◽  
J. Günther ◽  
L. Halbauer ◽  
M. Vollmer ◽  
A. Buchwalder ◽  
...  

The present study reports on the impact of abnormal grain growth (AGG) on the microstructural evolution following electron beam (EB) welding of Fe–Mn–Al–Ni shape memory alloy (SMA). Polycrystalline sheet-like material was EB-welded and a cyclic heat treatment, studied in previous work, was conducted for inducing AGG and a bamboo-like microstructure, respectively. Optical and electron microscopy were carried out to characterize the prevailing microstructure upon cyclic heat treatment. For characterization of the functional properties following AGG, a load increase test was conducted. The current results clearly show that good shape memory response can be obtained in Fe–Mn–Al–Ni SMA upon EB welding and subsequent post-heat treatment. These results further substantiate the potential use of conventional processing routes for Fe–Mn–Al–Ni SMA.


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