Effect of plasma nitriding temperature on microstructure and wear properties of electroless nickel‑boron coatings

Author(s):  
R. Tima ◽  
F. Mahboubi
Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 528 ◽  
Author(s):  
Hongzhi Yan ◽  
Linhe Zhao ◽  
Zhi Chen ◽  
Xuan Hu ◽  
Zhaojun Yan

This paper presents an auxiliary heating method to maintain a uniform specimen temperature and precisely control nitriding temperature during plasma nitriding. The surface properties and wear properties of AISI H11 steel treated by auxiliary heating plasma nitriding are investigated. Firstly, the specimens with different diffusion layers and different hardness levels are fabricated through changing the plasma nitriding temperature. Secondly, the surface properties of the plasma-nitrided H11 steel specimens are characterized by a scanning electron microscope (SEM), X-ray diffractometer, metallographic microscope and microhardness tester. The results show that the surface hardness of the plasma-nitrided specimen is almost twice as high as that of the untreated specimen. The thickness of diffusion layer increases with the increase of nitriding temperature. However, the surface hardness firstly increases and then decreases with the increase of the nitriding temperature. Finally, the wear properties of untreated and plasma-nitrided H11 steel specimens are investigated under different friction conditions. The results show that the plasma-nitriding method can significantly improve the wear resistance of AISI H11 steel. The friction coefficient fluctuations of the plasma-nitrided specimens are all lower than those of the untreated specimens. In addition, the wear rates of the plasma-nitrided specimens rise along with load, and reduce along with the sliding speed and friction temperature.


Author(s):  
Santosh Vitthal Bhaskar ◽  
Hari Narayan Kudal

In the present article, samples made of AISI 4140 steel, pre-treated with plasma nitriding (PN), and coated with different coatings like Titanium Carbonitride (TiCN), Aluminium Chromium Nitride (AlCrN), using Physical Vapor Deposition (PVD) technique, were investigated in terms of their microhardness, surface roughness, and dry sliding wear behaviour. Wear tests were performed with a pin-on-disc machine. Coatings were deposited on plasma nitrided samples. The wear behaviour, and wear mechanisms of TiCN- and AlCrN-coated, PN treated AISI 4140 specimens were investigated using a field emission Scanning Electron Microscope (SEM), equipped with an Energy Dispersive X-ray (EDX) analyzer. An SEM was used to study the surface morphology of the worn surfaces. Also, adhesion tests were conducted to investigate the adhesion quality of the coated specimens. The results of the investigation showed improved wear properties. Furthermore, the compound layer formed during nitriding was found to act as an intermediate hard layer, leading to superior sliding wear properties.


2013 ◽  
Vol 701 ◽  
pp. 370-374
Author(s):  
Yusliza Yusuf ◽  
Zulkifli Mohd Rosli ◽  
Jariah Mohamad Juoi ◽  
Zainab Mahamud ◽  
Kwan Wai Loon

Ti6Al4V alloy are among the most widely used materials in engineering applications. This is because their relatively beneficial properties. However, inadequate wear properties of Ti6Al4V alloy have largely constrained the application for this material. In this study, Plasma nitriding of the Ti6Al4V was performed using microwave plasma technique at 600°C for 1hour, 3 hours and 5 hours then followed with deposition of CrN on plasma nitrided samples for duplex coating purposes. Microstructural analysis and hardness measurement revealed that formation of Ti2N and TiN phases indicating the formation of compound layer is observed for substrate nitrided at temperature as low as 600°C 1 hour and a substantial increase on the surface hardness of plasma nitrided Ti6Al4V is observed with an increase of process time. The duplex coating obtained in this study has significant surface hardness property and superior as compared with CrN coatings deposited on as received Ti6Al4V.


2021 ◽  
Vol 105 (1) ◽  
pp. 309-318
Author(s):  
Chien Nguyen ◽  
Emil Svoboda ◽  
Jan Sedlacek ◽  
Josef Sedlak ◽  
Ales Polzer ◽  
...  

This study was conducted to investigate the effect of hybrid surface treatment composed of plasma nitriding (PN) and chromium nitride (CrN) coating on the friction-wear properties, the adhesion strength of AISI 316L stainless steel. The CrN coatings with the thickness of 1.0 µm and 2.2 µm were formed on the surfaces of both substrates with plasma nitriding (PN/CrN coating) and without plasma nitriding (CrN coating). The plasma nitriding, CrN coatings, and the hybrid treatment improved markedly the friction-wear properties of the stainless steel. The plasma nitriding generated a hardened layer between the soft substrate and the thin hard coatings and improved markedly friction-wear properties of the CrN-coated stainless steel and the adhesion of the CrN coatings.


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