Deformation mechanism and tribological behavior of hydrogen-free carburized layer on Ti-6Al-4V alloy
Industrial Lubrication and Tribology
ISSN: 0036-8792
Article publication date: 31 July 2020
Issue publication date: 1 February 2021
Abstract
Purpose
The purpose of this paper is to expound the relationship among microstructure, mechanical property, tribological behavior and deformation mechanism of carburized layer deposited on Ti-6Al-4V alloy by double-glow plasma hydrogen-free carburizing surface technology.
Design/methodology/approach
Morphologies and phase compositions of the carburized layer were observed by scanning electron microscope and X-ray diffraction. The micro-hardness tests were used to evaluate the surface and cross-sectional hardness of carburized layer. The reciprocating friction and wear experiments under various load conditions were implemented to investigate the tribological behavior of carburized layer. Moreover, scratch test with ramped loading pattern was carried out to illuminate the deformation mechanism of carburized layer.
Findings
Compared to substrate, the hardness of surface improved to ∼1,100 HV0.1, while the hardness profile of carburized layer presented gradual decrease from ∼1,100 to ∼300 HV0.1 within the distance of the total carburizing-affected region about 30 µm. The coefficient of friction, wear rate and wear morphology of carburized layer were analyzed. Scratch test indicated that the deformation process of carburized layer could be classified into three mechanisms (elastic, changing elastic–plastic and stable elastic–plastic mechanisms), and the deformation transition of the carburizing-affected region was from changing elastic–plastic to elastic mechanisms. Both the elastic and changing elastic–plastic mechanisms are conducive to the wearing course.
Originality/value
Using this technology, hydrogen embrittlement was avoided and wear resistance property of titanium alloy was greatly improved. Simultaneously, the constitutive relation during the whole loading process was deduced in terms of scratch approach, and the deformation mechanism of carburized layer was discussed from a novel viewpoint.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2019-0489/
Keywords
Acknowledgements
This project was supported by Natural Science Foundation for Excellent Young Scientists of Jiangsu Province, China (Grant No. BK20180068), China Postdoctoral Science Foundation funded project (Grant No. 2018M630555), the Fundamental Research Funds for the Central Universities, China (Grant No. NS2018039), Opening Project of Aero-engine Thermal Environment and Structure Key Laboratory of Ministry of Industry and Information Technology, China (Grant No. CEPE2019005).
Citation
Tian, T., Zhao, R., Wei, D., Yang, K. and Zhang, P. (2021), "Deformation mechanism and tribological behavior of hydrogen-free carburized layer on Ti-6Al-4V alloy", Industrial Lubrication and Tribology, Vol. 73 No. 1, pp. 68-73. https://doi.org/10.1108/ILT-11-2019-0489
Publisher
:Emerald Publishing Limited
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