Superelastic Behavior of Ti-Nb Alloys Obtained by the Laser Engineered Net Shaping (LENS) Technique

Materials

卷:13

Eduard Cesari¹  Anna Antolak-Dudka²  Tomasz Durejko²  Tomasz Czujko²  Damian Kalita³  Jan Dutkiewicz³  Piotr Bobrowski³  Łukasz Rogal³ 

[1] Department of Physics, University of Balearic Islands, E07122 Palma de Mallorca, Spain;

[2] Institute of Materials Science and Engineering, Faculty of Advanced Technology and Chemistry, Military University of Technology, 2, Gen. Kaliskiego Str., 00-908 Warsaw, Poland;

[3] Institute of Metallurgy and Materials Science, Polish Academy of Sciences, 25, Reymonta St., 30-059 Krakow, Poland;

关键词: additive manufacturing;    laser engineered net shaping (LENS), metastable β titanium alloys;    Ti–Nb alloys;    superelasticity;    deformation mechanisms;    oxygen effect;   

DOI  :  10.3390/ma13122827

来源: DOAJ

【 摘 要 】

The effect of Nb content on microstructure, mechanical properties and superelasticity was investigated for a series of Ti-xNb alloys, fabricated by the laser engineered net shaping method, using elemental Ti and Nb powders. The microstructure of as-deposited materials consisted of columnar β-phase grains, elongated in the built direction. However, due to the presence of undissolved Nb particles during the deposition process, an additional heat treatment was necessary. The observed changes in mechanical properties were explained in relation to the phase constituents and deformation mechanisms. Due to the elevated oxygen content in the investigated materials (2 at.%), the specific deformation mechanisms were observed at lower Nb content in comparison to the conventionally fabricated materials. This made it possible to conclude that oxygen increases the stability of the β phase in β–Ti alloys. For the first time, superelasticity was observed in Ti–Nb-based alloys fabricated by the additive manufacturing method. The highest recoverable strain of 3% was observed in Ti–19Nb alloy as a result of high elasticity and reverse martensitic transformation stress-induced during the loading.

【 授权许可】

Unknown