scholarly journals Electron beam welding of Fe–Mn–Al–Ni shape memory alloy: Microstructure evolution and shape memory response

2017 ◽  
Vol 10 (04) ◽  
pp. 1750043 ◽  
Author(s):  
P. Krooß ◽  
J. Günther ◽  
L. Halbauer ◽  
M. Vollmer ◽  
A. Buchwalder ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electron Beam ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Electron Beam Welding ◽  
Eb Welding ◽  
Cyclic Heat Treatment ◽  
Memory Response ◽  
Cyclic Heat ◽  
The Impact

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.

scholarly journals Effects of cyclic heat treatment and aging on superelasticity in oligocrystalline Fe-Mn-Al-Ni shape memory alloy wires

2017 ◽  
Vol 134 ◽  
pp. 66-70 ◽  
Author(s):  
H. Ozcan ◽  
Ji Ma ◽  
S.J. Wang ◽  
I. Karaman ◽  
Y. Chumlyakov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Cyclic Heat Treatment ◽  
Cyclic Heat

scholarly journals Abnormal Grain Growth Induced by Cyclic Heat Treatment and Fabrication of Cu-Based Shape Memory Alloy Single Crystal

Materia Japan ◽  
2019 ◽  
Vol 58 (3) ◽  
pp. 137-143
Author(s):  
Toshihiro Omori ◽  
Tomoe Kusama ◽  
Sumio Kise ◽  
Toyonobu Tanaka ◽  
Yoshikazu Araki ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Shape Memory Alloy ◽  
Single Crystal ◽  
Shape Memory ◽  
Grain Growth ◽  
Abnormal Grain Growth ◽  
Alloy Single Crystal ◽  
Cyclic Heat Treatment ◽  
Cyclic Heat

Heat Treatment Behavior of Tungsten Heavy Alloy

2006 ◽  
Vol 118 ◽  
pp. 35-40 ◽  
Author(s):  
Woon Hyung Baek ◽  
Moon Hee Hong ◽  
Eun Pyo Kim ◽  
Joon Woong Noh ◽  
Seong Lee ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Dynamic Properties ◽  
Weight Percent ◽  
Matrix Phase ◽  
Heavy Alloy ◽  
Tungsten Heavy Alloy ◽  
Cyclic Heat Treatment ◽  
Cyclic Heat ◽  
The Difference ◽  
The Impact

This paper focuses on the variations of static and dynamic properties of tungsten heavy alloy with heat treatment. The matrix phase of 93W-4.9Ni-2.1Fe (weight percent) has been penetrated into W/W grain boundaries during a cyclic heat treatment which consists of repeated isothermal holdings at 1150 °C and water quenching between them. By applying the cyclic heat treatment, the impact energy of tungsten heavy alloy is increased about three times from 57 to 170 J. When the tungsten heavy alloy is cyclically heat treated at 1150 °C and then re-sintered at 1485 °C, W/matrix interface is changed from round to undulated shape. The irregularity of the interface is increased with increasing the number of heat treatment cycles. From the measurement of the residual stress of W grains by X-ray diffraction, it is found that the irregularity of the interface is closely related with strain energy stemmed from the difference of thermal expansion coefficient between W particles and matrix phase. From dynamic ballistic test, it is found that the tungsten heavy alloy with undulated W grains forms many narrow fracture bands which are preferential for the self sharpening effect, thus, for the improvement of the penetration performance.

Effect of cyclic heat treatment on commercially pure titanium part fabricated by electron beam additive manufacturing

2019 ◽  
Vol 796 ◽  
pp. 300-306 ◽  
Author(s):  
Hyung-Ki Park ◽  
Tae-Wook Na ◽  
Jong Min Park ◽  
Yanghoo Kim ◽  
Gun-Hee Kim ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electron Beam ◽  
Additive Manufacturing ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Cyclic Heat Treatment ◽  
Commercially Pure ◽  
Cyclic Heat

Influence of local heat treatment on mechanical characteristics of welded joints of intermetallic tial system obtained by electron beam welding

2020 ◽  
Vol 2020 (9) ◽  
pp. 36-41
Author(s):  
L.M. Lobanov ◽  
◽  
E.A. Asnis ◽  
N.V. Piskun ◽  
E.L. Vrzhyzhevskyi ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Electron Beam ◽  
Welded Joints ◽  
Mechanical Characteristics ◽  
Electron Beam Welding ◽  
Local Heat ◽  
Local Heat Treatment

Oxidation resistance of TiAl alloy improved by hot-pack rolling and cyclic heat treatment

2021 ◽  
pp. 111196
Author(s):  
Tian Shiwei ◽  
He Anrui ◽  
Liu Jianhua ◽  
Zhang Yefei ◽  
Yang Yonggang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Oxidation Resistance ◽  
Tial Alloy ◽  
Cyclic Heat Treatment ◽  
Pack Rolling ◽  
Cyclic Heat ◽  
Hot Pack

Microstructure and properties of Ni-Co-Mn-Al magnetic shape memory alloy prepared by direct laser deposition and heat treatment

2021 ◽  
Vol 141 ◽  
pp. 107119
Author(s):  
Wuming Jia ◽  
Suiyuan Chen ◽  
Luting Wang ◽  
Fanmin Shang ◽  
Xinru Sun ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Laser Deposition ◽  
Magnetic Shape Memory ◽  
Direct Laser Deposition ◽  
Microstructure And Properties ◽  
Magnetic Shape Memory Alloy ◽  
Direct Laser

scholarly journals Electron beam welding of rectangular copper wires applied in electrical drives

2021 ◽  
Author(s):  
Tamás Tóth ◽  
Jonas Hensel ◽  
Sven Thiemer ◽  
Philipp Sieber ◽  
Klaus Dilger
Keyword(s):  
Electron Beam ◽  
Oxygen Content ◽  
Electron Beam Welding ◽  
Base Material ◽  
Fusion Welding ◽  
Eb Welding ◽  
Technological Parameters ◽  
Low Level ◽  
Residual Oxygen ◽  
Ofe Copper

AbstractThe so-called hairpin winding technology, which is specially tailored to electrical traction components, deploys rectangular plug-in copper wires in the stator. The fusion welding of the adjacent wire ends is associated with challenges due to the high thermal conductivity as well as the porosity formation of the copper. During this study, the electron beam (EB) welding of electrolytic tough pitch (ETP) and oxygen-free electronic grade (OFE) copper connectors was investigated. Subsequently, the specimens underwent X-ray computed tomography (CT) and metallographic examinations to characterize the joints. It was discovered that the residual oxygen content of the base material is responsible for the pore formation. With only a very low level of oxygen content in the copper, a porosity- and spatter-free welding can be reproducibly realized using the robust EB welding technology, especially for copper materials. By optimizing the parameters accordingly, joints exhibiting a low level of porosity were achieved even in the case of the alloy containing a high amount of residual oxygen. Beyond this, detailed analyses in terms of pore distribution were carried out and a good correlation between technological parameters and welding results was determined.

scholarly journals Laser Powder Bed Fusion Processing of Fe-Mn-Al-Ni Shape Memory Alloy—On the Effect of Elevated Platform Temperatures

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 185
Author(s):  
Felix Clemens Ewald ◽  
Florian Brenne ◽  
Tobias Gustmann ◽  
Malte Vollmer ◽  
Philipp Krooß ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Crack Formation ◽  
Microstructural Analysis ◽  
Tensile Load ◽  
Grain Structure ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Cyclic Heat Treatment ◽  
Powder Bed ◽  
Cyclic Heat

In order to overcome constraints related to crack formation during additive processing (laser powder bed fusion, L-BPF) of Fe-Mn-Al-Ni, the potential of high-temperature L-PBF processing was investigated in the present study. The effect of the process parameters on crack formation, grain structure, and phase distribution in the as-built condition, as well as in the course of cyclic heat treatment was examined by microstructural analysis. Optimized processing parameters were applied to fabricate cylindrical samples featuring a crack-free and columnar grained microstructure. In the course of cyclic heat treatment, abnormal grain growth (AGG) sets in, eventually promoting the evolution of a bamboo like microstructure. Testing under tensile load revealed a well-defined stress plateau and reversible strains of up to 4%.

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