Corrosion behavior of NiTi alloy subjected to femtosecond laser shock peening without protective coating in air environment

2020 ◽  
Vol 501 ◽  
pp. 144338 ◽  
Author(s):  
Hao Wang ◽  
Jens Jürgensen ◽  
Peer Decker ◽  
Zhiyong Hu ◽  
Kai Yan ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Corrosion Behavior ◽  
Protective Coating ◽  
Niti Alloy ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Shock Peening

scholarly journals Corrosion Behavior of NiTi Alloys Fabricate by Selective Laser Melting Subjected to Femtosecond Laser Shock Peening

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1078
Author(s):  
Long Ma ◽  
Wanqing Li ◽  
Yongzhi Yang ◽  
Yuanxue Ma ◽  
Kai Luo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Femtosecond Laser ◽  
Selective Laser Melting ◽  
Niti Alloy ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Laser Melting ◽  
Corrosion Failure ◽  
Niti Alloys ◽  
Shock Peening

NiTi alloys are commonly used in many fields such as aerospace, mechanical engineering due to their excellent mechanical properties and shape memory effect. In recent years, the emergence of selective laser melting (SLM) technology provides a new method for the preparation of NiTi parts. But the surface corrosion failure of SLM-NiTi is the most common problem. This paper mainly focuses on the research of femtosecond laser shock peening of the surface of SLM-NiTi alloy to improve the corrosion resistance. Selecting different scanning space (1 μm, 3 μm, 5 μm, 10 μm), and analyze the surface morphology of the material through the OM, SEM, EDS and white light interferometer, and investigate the surface nanohardness and corrosion resistance through nanoindentation and electrochemical testing. The research results show that part of the TiO2 is formed under different scanning spaces, and part of NiO is formed when the scanning space is 1μm. At the same time, it is found that the sample under the condition of 10 μm has the most excellent corrosion resistance and nanohardness. The nanohardness reaches 1303 ± 40 HV and the corrosion current density reaches 1.45 ± 0.1 × 10−9 A·cm−2. Proper femtosecond laser treatment can effectively improve the surface strength and corrosion resistance of the NiTi alloys.

scholarly journals Investigation of Corrosion Behaviour of Aluminium Alloy Subjected to Laser Shock Peening without a Protective Coating

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
U. Trdan ◽  
J. Grum
Keyword(s):  
Shock Waves ◽  
Protective Coating ◽  
Corrosion Behaviour ◽  
Laser Shock Peening ◽  
Anodic Current Density ◽  
Strain Rates ◽  
Laser Shock ◽  
Near Surface ◽  
Shock Peening ◽  
Chloride Environment

The effect of shock waves and strain hardening of laser shock peening without protective coating (LSPwC) on alloy AA 6082-T651 was investigated. Analysis of residual stresses confirmed high compression in the near surface layer due to the ultrahigh plastic strains and strain rates induced by multiple laser shock waves. Corrosion tests in a chloride environment were carried out to determine resistance to localised attack, which was also verified on SEM/EDS. OCP transients confirmed an improved condition, that is, a more positive and stable potential after LSPwC treatment. Moreover, polarisation resistance of the LSPwC treated specimen was by a factor of 25 higher compared to the untreated specimen. Analysis of voltammograms confirmed an improved enhanced region of passivity and significantly smaller anodic current density of the LSPwC specimen compared to the untreated one. Through SEM, reduction of pitting attack at the LSPwC specimen surface was confirmed, despite its increased roughness.

Martensitic Transformation in Temporally Shaped Femtosecond Laser Shock Peening 304 Steel

2021 ◽  
pp. 150855
Author(s):  
Yiling Lian ◽  
Yanhong Hua ◽  
Jingya Sun ◽  
Qingsong Wang ◽  
Zhicheng Chen ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Femtosecond Laser ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Shock Peening

scholarly journals Laser Shock Peening of Ti6Al4V Alloy with Combined Nanosecond and Femtosecond Laser Pulses

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 26
Author(s):  
Rujian Sun ◽  
Guangzhi He ◽  
Hailin Bai ◽  
Jianfeng Yan ◽  
Wei Guo
Keyword(s):  
Femtosecond Laser ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Laser Shock Peening ◽  
Metallic Materials ◽  
Laser Shock ◽  
Laser Absorption ◽  
Shock Peening ◽  
Surface Morphologies ◽  
Equiaxed Grains

Laser shock peening (LSP) with nanosecond or femtosecond laser pulses is applied to improve the mechanical properties of metallic materials. Thus, it is necessary to compare the effects of different processing methods on microstructure changes and property improvement. In this study, nanosecond LSP (NLSP), femtosecond LSP (FLSP), and LSP with combined nanosecond and femtosecond laser pulses (F-NLSP) are conducted on Ti6Al4V alloys to compare the surface morphologies, in-depth microstructures, and nanohardness changes. In FLSP, the peened surface is smooth, and the affected depth is limited near the peened surface. NLSPed and F-NLSPed samples present rough surfaces due to the severe ablation process. Small equiaxed grains with no preferred grain orientation are denser in F-NLSPed samples than that in NLSPed samples. Compared with NLSPed samples, the affected depth and amplitude of in-depth nanohardness are larger in F-NLSPed samples. This is attributed to the increased laser absorption of incident laser on the treated surface by femtosecond laser pulses. The results in this study show the effects of different LSP methods and provide chances in engineering potentials for material property improvements.

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