Work

Mechanism of improving cyclic tensile behavior and corrosion resistance of laser-treated NiTi shape memory alloys

Year: 2025

Type: article

Abstract: This study employed a 250 W laser surface treatment to improve the cyclic tensile behavior and corrosion resistance of NiTi shape memory alloy used in high-temperature and high-pressure boilers. The treatment resulted in the decomposition of Ti-C-O particles in melt pool, subsequently forming a metastable solid solution structure which inhibited sources of microgalvanic corrosion. The elastic modulus of the material was enhanced to 44.19 GPa, and the pinning of dislocations by solid solution interstitial atoms (C/O) led to a reduction in residual deformation by 21.2%. The improved corrosion resistance can be attributed to the formation of a dense bipolar passivation film. This film resulted in a 96% decrease in hole concentration in the p-type region, a sixfold increase in charge transfer resistance, and a 97% decrease in the corrosion rate. Comparative experiments revealed that the use of a 500 W laser, due to thermal accumulation, produced porosity defects, compromising the integrity of the material and leading to inferior performance.

Source: International Journal of Electrochemical Science

DOI: 10.1016/j.ijoes.2025.101190

Authors: Xinmei Li, Wen Li, Luning Zhang, Tianxiang Xue, Shuai Suo, Dongting Wu

Institutions: State Grid Corporation of China (China), State Grid Shandong Electric Power Company (China), Shandong University

Language: English

Topic: Shape Memory Alloy Transformations

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,670

Funder: Natural Science Foundation of Shandong Province