scholarly journals Fabrication and Corrosion Resistance of the Ti-rich Alloyed Layer on the Surface of NiTi Alloys

2017 ◽  
pp. 2376-2388 ◽  
Author(s):  
Hairui Wu ◽  
Keyword(s):  
Corrosion Resistance ◽  
Alloyed Layer ◽  
Niti Alloys

An investigation on the possibility to improve the corrosion and cavitation resistance of SS304 steel by NiTi coatings

2021 ◽  
Vol 35 (04) ◽  
pp. 2150057
Author(s):  
Qunfeng Zeng ◽  
Khashayar Khanlari ◽  
Naiming Lin
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Niti Alloy ◽  
Preliminary Investigation ◽  
Industrial Applications ◽  
Cavitation Resistance ◽  
Niti Alloys ◽  
Materials Used ◽  
Ss 304 ◽  
Increasing Load

Equiatomic and near equiatomic NiTi alloys, showing good mechanical and thermal shape memory properties, are widely exploited in different industrial applications. In addition, NiTi alloys have promising anti-cavitation and corrosion-resistance properties. These advantages have provided opportunities to exploit NiTi alloys as the coatings for protecting materials used in the industrial applications. This study is a preliminary investigation aiming to evaluate the feasibility to form NiTi alloy coatings on SS304 steel by tungsten inert argon arc welding (TIG) technology. The microstructure analysis shows that the crystalline phases in NiTi coatings on SS 304 steel are TiNi-B2, TiNi-B19’ and Ni3Ti. The potential of the NiTi coatings to enhance the corrosion resistance and cavitation resistance behaviors of steel exposed to seawater is studied. NiTi coatings, with two different thicknesses of about 1.2 and 2 mm, having homogenous microstructures were successfully deposited on SS304 steel using TIG technology. Results of tests, done in aqueous solutions simulating seawater, showed that the formation of the oxide films on the surface of NiTi coatings increased the corrosion resistance and wear resistance and decreased the damage caused by the cavitation. Moreover, it was understood that the NiTi coatings with 2 mm in thickness show the superior performances than those with 1.2 mm in thickness. The tribological mechanisms responsible for the unique properties of NiTi alloy coatings were investigated. The wear-resistance behaviors of NiTi alloy coatings are greatly influenced by the friction conditions. Increasing load decreased CoF and the wear rate of the coatings were almost constant, which was attributed to the pseudoelasticity of NiTi alloy. The attractive properties of NiTi alloys that makes it most influential materials for industrial applications have also been discussed.

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.

Improving corrosion resistance of Q235 steel by Ni-Cr alloyed layer

2012 ◽  
Vol 27 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Jun Huang ◽  
Pingze Zhang ◽  
Hongyan Wu ◽  
Qiang Bi
Keyword(s):  
Corrosion Resistance ◽  
Alloyed Layer ◽  
Q235 Steel

Microstructure and corrosion resistance behavior of Cr-Nb alloyed layer on low carbon steel

2015 ◽  
Vol 66 (12) ◽  
pp. 1480-1487 ◽  
Author(s):  
Y.-M. Zhu ◽  
P.-Z. Zhang ◽  
X.-F. Wei ◽  
D.-B. Wei ◽  
X.-H. Chen ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
Alloyed Layer ◽  
Low Carbon

scholarly journals Novel Super-Elastic Materials for Advanced Bearing Applications

2014 ◽  
Vol 89 ◽  
pp. 1-9 ◽  
Author(s):  
Christopher Della Corte
Keyword(s):  
Corrosion Resistance ◽  
Niti Alloy ◽  
Load Capacity ◽  
High Hardness ◽  
Large Strains ◽  
Aqueous Corrosion ◽  
Niti Alloys ◽  
Tribological Surfaces ◽  
Aqueous Corrosion Resistance ◽  
Bearing Materials

Tribological surfaces of mechanical components encounter harsh conditions in terrestrial, marine and aerospace environments. Brinell denting, abrasive wear and fatigue often lead to life-limiting bearing and gear failures. Novel superelastic materials based upon Nickel-Titanium (NiTi) alloys are an emerging solution. NiTi alloys are intermetallic materials that possess characteristics of both metals and ceramics. NiTi alloys have intrinsically good aqueous corrosion resistance (they cannot rust), high hardness, relatively low elastic modulus, are chemically inert and readily lubricated. NiTi alloys also belong to the family of superelastics and, despite high hardness, are able to withstand large strains without suffering permanent plastic deformation. In this paper, the use of a hard, resilient NiTi alloy for corrosion-proof, shockproof bearing and gear applications is presented. Through a series of bearing and gear development projects, it is demonstrated that NiTi’s unique blend of material properties lead to significantly improved load capacity, reduced weight and intrinsic corrosion resistance not found in any other bearing materials. NiTi thus represents a new materials solution to demanding tribological applications.

Mechanical Properties of Nanoceramic Zirconia Coatings on NiTi Orthodontic Wires

2016 ◽  
Vol 97 ◽  
pp. 147-152 ◽  
Author(s):  
Natalia Isabel de Azevedo Lopes ◽  
Leandro de Arruda Santos ◽  
Vicente Tadeu Lopes Buono
Keyword(s):  
Corrosion Resistance ◽  
Shape Memory ◽  
Mechanical Response ◽  
Crack Nucleation ◽  
Orthodontic Wires ◽  
Nickel Ions ◽  
X Ray ◽  
Three Point Bending ◽  
Force Microscopy ◽  
Niti Alloys

Nickel-titanium (NiTi) alloys have been largely applied in biomedical devices due to their special properties of superelasticity and shape memory. Even though NiTi generally displays good corrosion resistance and biocompatibility, mechanical fatigue and fretting-corrosion resistance remain important challenges in a number of applications, since it can accelerate nickel ions releasing, that have been reported as cytotoxic, mutagenic, and allergenic. This study aims to develop an appropriate coating to help delaying crack nucleation and corrosion in NiTi alloys. Zirconia (ZrO2) coating stands as a good candidate to improve the corrosion and wear resistance of metallic substrates and, in this work, it was obtained by electrodeposition on NiTi superelastic and shape memory orthodontic wires. The surface morphology and the chemical composition of the coated samples were evaluated using scanning electron microscopy (SEM) with energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), and atomic force microscopy (AFM). The mechanical response was evaluated by three-point bending tests. The results showed that the ZrO2 layer was uniform and well adhered to the NiTi subtract. Additionally, it was observed that this coating was capable of undergoing severe deformation without cracking, indicating a potential increase in fatigue resistance of the conjugate.

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