Microstructure and Transformation Behavior of in-situ Shape Memory Alloys by Selective Laser Melting Ti–Ni Mixed Powder

2013 ◽  
Vol 29 (9) ◽  
pp. 863-867 ◽  
Author(s):  
Baicheng Zhang ◽  
Jing Chen ◽  
Christian Coddet
Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1683 ◽  
Author(s):  
Xiebin Wang ◽  
Sergey Kustov ◽  
Jan Van Humbeeck

Due to unique functional and mechanical properties, NiTi shape memory alloys are one of the most promising metallic functional materials. However, the poor workability limits the extensive utilization of NiTi alloys as components of complex shapes. The emerging additive manufacturing techniques provide high degrees of freedom to fabricate complex structures. A freeform fabrication of complex structures by additive manufacturing combined with the unique functional properties (e.g., shape memory effect and superelasticity) provide great potential for material and structure design, and thus should lead to numerous applications. In this review, the unique microstructure that is generated by selective laser melting (SLM) is discussed first. Afterwards, the previously reported transformation behavior and mechanical properties of NiTi alloys produced under various SLM conditions are summarized.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2696
Author(s):  
Igor Polozov ◽  
Anatoly Popovich

This paper presents the results of selective laser melting (SLM) process of a nitinol-based NiTiNb shape memory alloy. The eutectic alloy Ni45Ti45Nb10 with a shape memory effect was obtained by SLM in-situ alloying using a powder mixture of NiTi and Nb powder particles. Samples with a high relative density (>99%) were obtained using optimized process parameters. Microstructure, phase composition, tensile properties, as well as martensitic phase transformations temperatures of the produced alloy were investigated in as-fabricated and heat-treated conditions. The NiTiNb alloy fabricated using the SLM in-situ alloying featured the microstructure consisting of the NiTi matrix, fine NiTi+β-Nb eutectics, as well as residual unmelted Nb particles. The mechanical tests showed that the obtained alloy has a yield strength up to 436 MPa and the tensile strength up to 706 MPa. At the same time, in-situ alloying with Nb allowed increasing the hysteresis of martensitic transformation as compared to the alloy without Nb addition from 22 to 50 °C with an increase in Af temperature from −5 to 22 °C.


2018 ◽  
Vol 146 ◽  
pp. 246-250 ◽  
Author(s):  
Xiebin Wang ◽  
Mathew Speirs ◽  
Sergey Kustov ◽  
Bey Vrancken ◽  
Xiaopeng Li ◽  
...  

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