Effect of N2/Ar gas flow ratios on the nitrided layers by direct current arc discharge

Li, X.; Sun, Dongbai; Zheng, Xiaohong; Ren, Zhenan

doi:10.1016/j.matlet.2007.04.109

Cited by 11 publications

(5 citation statements)

References 11 publications

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“…Plasma nitriding treatments for titanium alloys are typically carried out at 700-1100°C for 6-80 hours. The atmosphere is composed of a nitrogen containing mixture, for example, N 2 , N 2 -Ar, N 2 -H 2 , or N 2 -NH 3 mixtures, with pressures that vary in the range of 0.5-1.3 kPa [18][19][20][21][22]. In addition to the nitriding time and temperature, the pressure and composition of the nitriding gas also have a significant effect on the microstructure of plasma-nitrided titanium alloys [15,17].…”

Section: Fundamentals Of Plasma Nitridingmentioning

confidence: 99%

“…Plasma nitriding of titanium alloys is typically carried out in the temperature range of 700-1100°C for 6-80 hours in a nitrogen-containing medium (N 2 , N 2 -Ar, N 2 -H 2 , or N 2 -NH 3 ) [18][19][20][21][22]. The high temperatures involved in the process lead to grain growth, overaging, and microstructural transformations in titanium substrates that decrease the fatigue strength and ductility [10,22,23].…”

Section: Introductionmentioning

confidence: 99%

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Plasma Nitriding of Titanium Alloys

Edrisy¹,

Farokhzadeh²

2016

Plasma Science and Technology - Progress in Physical States and Chemical Reactions

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Titanium alloys are found in many applications where weight saving, strength, corrosion resistance, and biocompatibility are important design priorities. However, their poor tribological behavior is a major drawback, and many surface engineering processes have been developed to enhance wear in titanium alloys such as nitriding. Plasma (ion) nitriding, originally developed for ferrous alloys, has been adopted to address wear concerns in titanium alloys. Plasma nitriding improves the wear resistance of titanium alloys by the formation of a thin surface layer composed of TiN and Ti 2 N titanium nitrides (e.g., compound layer). Nonetheless, plasma nitriding treatments of titanium alloys typically involve high temperatures (700-1100°C) that promote detrimental microstructural changes in titanium substrates, formation of brittle surface layers, and deterioration of mechanical properties especially fatigue strength. This chapter summarizes the previous and ongoing investigations in the field of plasma nitriding of titanium alloys, with particular emphasis on the authors' recent efforts in optimization of the process to achieve tribological improvements while maintaining mechanical properties. The development of low-temperature plasma nitriding treatments for α + β and near-β titanium alloys and further wear improvements by alteration of near-surface microstructure prior to nitriding are also briefly reviewed.

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Section: Fundamentals Of Plasma Nitridingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Plasma Nitriding of Titanium Alloys

Edrisy¹,

Farokhzadeh²

2016

Plasma Science and Technology - Progress in Physical States and Chemical Reactions

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“…The reduced amount of TiN in the coating is the main reason that the coating hardness decreases along the depth direction. It should be pointed out that the nitrided layer prepared on stainless steel substrate by ESD process has relatively low hardness value compared with that prepared on pure titanium substrate by DC nitrogen arc discharge process [10]. It is mainly attributed to the dilution of the deposit with the stainless steel substrate to form ferrite (␣-FeCr) phase in the nitrided layer.…”

Section: Element Distribution Of Deposition Coatingmentioning

confidence: 98%

“…In view of the superior mechanical properties and high wear resistance, cermet coatings with TiN find wide application in industry, since TiN possesses ultrahigh hardness as well as chemical and metallurgical stability. Currently, several surface treatment techniques for preparing the cermet and composite coatings with TiN have been reported, such as ion implantation [1], chemical vapor deposition (CVD) [2,3], physical vapor deposition (PVD) [4,5], laser surface nitriding [6][7][8], direct current (DC) nitrogen arc discharge [9,10] and so on. The electrospark deposition (ESD) is also a surface treatment technique to produce hard and wear-resistant coatings on metallic components in engineering [11][12][13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Microstructures and wear properties of TiN-based cermet coating deposited on 1Cr18Ni9Ti stainless steel by electrospark process

Sun

Zheng

et al. 2008

Materials Science and Engineering: A

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“…Some nitride phases, such as aluminum nitride (AlN) and titanium nitride (TiN, Ti 2 N), are highly corrosion resistant, so they do not degrade or deteriorate when exposed to body fluids or other corrosive environments in the human body. A widely used process to improve the surface properties of titanium alloys is gas nitriding, which is carried out in the gas phase in the temperature range of 800 °C-1050 °C [9,10] in a nitrogenous environment (N 2 , N 2 -Ar, N 2 -H 2 , or N 2 -NH 3 ) [11][12][13][14][15] with a nitriding time of 6 to 80 h. However, gas nitriding requires high temperature for dissociation of bonds and leads to fatigue deterioration. The surface of the sample after gas nitriding usually has a high thickness compound layer, which needs to be polished, or surface finished before use.…”

Section: Introductionmentioning

confidence: 99%

Effect of pulse frequency on the surface properties and corrosion resistance of a plasma-nitrided Ti-6Al-4V alloy

Kaewnisai,

Chingsungnoen,

Poolcharounsin

et al. 2023

Mater. Res. Express

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In this work, Ti-6Al-4V alloy, commonly used as implant material in biomedical applications, was treated by plasma nitriding. The nitriding process was carried out using an N2-H2 plasma (1000:500 sccm) at an operating pressure of about 866 Pa. The current regulation was about 1.8 A, the negative voltage was about 480-500 V, and the power was 840-940 W. The nitriding temperature was maintained at 650±5 ºC, and the nitriding time was 240 min. Bipolar pulse frequencies were varied at 25, 50, 100, 150, and 200 kHz. Analysis by grazing incidence X-ray diffraction spectrometer (GI-XRD) revealed the presence of δ-TiN and ε-Ti2N phases in all nitrided samples. The hardness depth profile was measured with a penetration depth of about 5 nm using the enhanced stiffness procedure (ESP). The results showed that all the nitrided samples had a surface hardness approximately three times that of the unnitrided sample. This result is consistent with that from glow discharge emission spectroscopy (GD-OES), which confirmed the diffusion distance of nitrogen atoms from the surface of about 5 μm. After plasma nitriding, the surface roughness tended to increase, resulting in an increase in the water contact angle (WCA) and a decrease in the work of adhesion. The specific wear rate (ball-on-disk) of all nitrided samples decreased and was significantly lower at a bipolar pulse frequency of 50 kHz. This result is consistent with the stability of the coefficient of friction (CoF) after 6000 sliding cycles. Moreover, the nitrided sample at 50 kHz exhibited the lowest corrosion current density in artificial saliva based on the Tafel potential polarization method.

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Effect of N2/Ar gas flow ratios on the nitrided layers by direct current arc discharge

Cited by 11 publications

References 11 publications

Plasma Nitriding of Titanium Alloys

Plasma Nitriding of Titanium Alloys

Microstructures and wear properties of TiN-based cermet coating deposited on 1Cr18Ni9Ti stainless steel by electrospark process

Effect of pulse frequency on the surface properties and corrosion resistance of a plasma-nitrided Ti-6Al-4V alloy

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