Corrosion and tribological performance of PTFE-coated electroless nickel boron coatings

Wan, Yong; Yu, Yankun; Cao, Lei; Zhang, M.; Gao, Jinwei; Qi, Caixia

doi:10.1016/j.surfcoat.2016.09.001

Cited by 74 publications

(38 citation statements)

References 28 publications

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“…In a previous study [36], PTFE/Ni-B coated steel was immersed in 3.5% NaCl solution for different times, and images showed that the untreated steel became corroded after a few days but no changes occurred in the PTFE/Ni-B coated steel after 7 days immersion in 3.5% NaCl solution. The micrographs of the uncoated substrate show some micro cracks on the surface of the substrate while the PTFE coating ( Figure 1) shows a uniform and smooth distributed layer on the SS with no discontinuous deposition or cracks observed by SEM, which is in line with previously reported studies [36,37]. PTFE nanoparticles can fill the micropores, and a compact, smooth and regular surface morphology can be obtained, which generally decreases the surface roughness [38,39].…”

Section: Characterizationsupporting

confidence: 90%

Characterization of PTFE Film on 316L Stainless Steel Deposited through Spin Coating and Its Anticorrosion Performance in Multi Acidic Mediums

et al. 2020

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Polytetrafluoroethylene (PTFE) was coated on 316L stainless steel (SS) substrate through a spin coating technique to enhance its corrosion resistance properties in hydrochloric acid (HCl) and nitric acid (HNO3) medium. Scanning electron microscopy (SEM) revealed the morphology of the coated and uncoated substrates and showed a uniform and crack-free PTFE coating on 316L SS substrate, while a damaged surface with thick corrosive layers was observed after the electrochemical test on the uncoated sample. However, an increased concentration of HCl and HNO3 slightly affected the surface morphology by covering the corrosive pits. An atomic force microscope (AFM) showed that the average surface roughness on 316L SS and PTFE coating was 26.3 nm and 24.1 nm, respectively. Energy dispersive X-ray spectroscopy (EDS) was used for the compositional analysis, which confirmed the presence of PTFE coating. The micro Vickers hardness test was used to estimate the hardness of 316L SS and PTFE-coated substrate, while the scratch test was used to study the adhesion properties of PTFE coating on 316L SS. The anticorrosion measurements of 316L SS and PTFE-coated substrates were made in various HCl and HNO3 solutions by using the electrochemical corrosion test. A comparison of the corrosion performance of PTFE-coated substrate with that of bare 316L SS substrate in HCl medium showed a protection efficiency (PE) of 96.7%, and in the case of HNO3 medium, the PE was 99.02%, by slightly shifting the corrosion potential of the coated sample towards the anodic direction.

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Section: Characterizationsupporting

confidence: 90%

Characterization of PTFE Film on 316L Stainless Steel Deposited through Spin Coating and Its Anticorrosion Performance in Multi Acidic Mediums

et al. 2020

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“…Similar results have been also observed on inclusion of B 4 C nano-particles [31]. Impregnation of Ni-B coatings with PTFE (40%) results in a COF as low as <0.1 in non-lubricated, as well as 3.5% NaCl lubricated sliding condition [32]. Electroless Ni-B coatings have been applied in greaseless guns and barrel bores that are subjected to hostile environments proving to be a suitable replacement to chromium [33].…”

supporting

confidence: 67%

Comparative Study of Tribological Behavior of Electroless Ni–B, Ni–B–Mo, and Ni–B–W Coatings at Room and High Temperatures

et al. 2018

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Ni-B alloys deposited by the electroless method are considered to be hard variants of the electroless nickel family. Inclusion of Mo or W to form ternary alloys improves the thermal stability of electroless nickel coatings. Therefore, in the present work, Ni-B, Ni-B-Mo, and Ni-B-W coatings are deposited; and their tribological behavior at room and high temperatures are investigated. Electroless Ni-B, Ni-B-Mo, and Ni-B-W coatings are deposited on AISI 1040 steel substrates. The coatings are heat treated to improve their mechanical properties and crystallinity. Tribological behavior of the coatings is determined on a pin-on-disc type tribological test setup using various applied normal loads (10-50 N) and sliding speeds (0.25-0.42 m/s) to measure wear and coefficient of friction at different operating temperatures (25 • C-500 • C). Ni-B-W coatings are observed to have higher wear resistance than Ni-B or Ni-B-Mo coatings throughout the temperature range considered. Although for coefficient of friction, no such trend is observed. The worn surface of the coatings at 500 • C is characterized by lubricious oxide glazes, which lead to enhanced tribological behavior compared with that at 100 • C. A study of the coating characteristics such as composition, phase transformations, surface morphology, and microhardness is also carried out prior to tribological tests. Lubricants 2018, 6, 67 2 of 17The Ni-B alloy coating has higher wear resistance and low COF compared with Ni-P alloy [23]. This is attributed to the high hardness, self-lubricating microstructure and columnar growths [24]. Consequently, a reduction in the actual contact area takes place, thereby improving the tribological characteristics [25]. Suitable treatments of Ni-B coatings may even lead to microhardness that is equivalent to chromium [26]. As a result of this, Ni-B coatings are considered to be a suitable alternative to chromium, which has environmental concerns. Friction and wear characteristics of magnesium and aluminium alloys that are widely used commercially could be improved by Ni-B alloy deposition [27]. An improvement of tribological behavior of Ni-B coatings is also achieved on inclusion of W or Mo [28,29]. In fact, co-deposition of nano Al 2 O 3 results in an increase in microhardness bỹ 290 HV 100 [30]. The mass loss and COF of Ni-B-Al 2 O 3 coatings is almost six and two times lower, respectively, in comparison with Ni-B alloy in as-deposited state. Similar results have been also observed on inclusion of B 4 C nano-particles [31]. Impregnation of Ni-B coatings with PTFE (40%) results in a COF as low as <0.1 in non-lubricated, as well as 3.5% NaCl lubricated sliding condition [32]. Electroless Ni-B coatings have been applied in greaseless guns and barrel bores that are subjected to hostile environments proving to be a suitable replacement to chromium [33]. Recent studies have focused attention on duplex and multi-layer coatings that possess intermediate/enhanced tribological characteristics compared with the single layered binary alloys [34,35]....

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“…[31][32][33] The tribological and corrosion properties of Ni-B coatings could be improved by the impregnation of PTFE. 34 For 40% PTFE/Ni-B coatings, it is seen that under dry as well as under 3.5% NaCl solution, the substrate steel is able to withstand a test duration of 3600 s with COF as low as <0.1. 34 In a recent study, the tribological behavior of as-plated Ni-B coating was explored up to a temperature of 500 C and the best wear resistance was observed at 300 C. 35 Since Ni-B coatings have been found to be superior to Ni-P coatings at room temperature tests, it is therefore necessary to extend their capabilities to cater into the high temperature domain.…”

Section: Introductionmentioning

confidence: 97%

Tribological behavior of electroless Ni–B–W coating at room and elevated temperatures

Mukhopadhyay

Barman

Sahoo

2018

Proceedings of the Institution of Mechanical Engineers, Part J:

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Sodium borohydride reduced electroless NiB coatings possess high hardness, wear resistance, and low coefficient of friction. They are found to be suitable candidates for wear reduction of mechanical components. In a quest to achieve enhanced tribological behavior and high thermal stability, the present work reports the inclusion of W to NiB coatings. Electroless method is employed for NiB -W coating deposition on AISI 1040 steel specimens. Post deposition, the coatings are heat treated at 350 C, 400 C, and 450 C. Deposit characterization is carried out using energy-dispersive X-ray analysis, X-ray diffraction, and scanning electron microscopy. Inclusion of W leads to an increase in microhardness and thermal stability of NiB coatings. The tribological behavior of as-deposited and heat-treated NiB -W coatings are investigated at room and elevated temperatures (100 C, 300 C, and 500 C). Heat-treated coatings show lower wear rate at room temperature compared to as-deposited ones but the coefficient of friction increases. Tribological test results at elevated temperatures suggest an improvement in the wear resistance and coefficient of friction at 300 C and 500 C in comparison with 100 C. Phase transformation study post wear test indicate microstructural changes in the coating due to the in situ heat treatment at high temperature. The tribological behavior of the coatings at 100 C and 300 C is mainly governed by the loose wear debris and formation of debris patches, respectively. Whereas at 500 C, formation of protective tribo-oxide patches is also observed.

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Corrosion and tribological performance of PTFE-coated electroless nickel boron coatings

Cited by 74 publications

References 28 publications

Characterization of PTFE Film on 316L Stainless Steel Deposited through Spin Coating and Its Anticorrosion Performance in Multi Acidic Mediums

Characterization of PTFE Film on 316L Stainless Steel Deposited through Spin Coating and Its Anticorrosion Performance in Multi Acidic Mediums

Comparative Study of Tribological Behavior of Electroless Ni–B, Ni–B–Mo, and Ni–B–W Coatings at Room and High Temperatures

Tribological behavior of electroless Ni–B–W coating at room and elevated temperatures

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