Langmuir probe characterization of nitrogen plasma for surface nitriding of AISI-4140 steel

Shah, Miral; Saleem, Murtaza; Ahmad, Riaz; Zakaullah, M.; Qayyum, A.; Murtaza, Ghulam

doi:10.1016/j.jmatprotec.2007.08.025

Cited by 29 publications

(17 citation statements)

References 20 publications

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“…Such behaviour can be explained by the fact that the indentation depth increases with applied load leading to a higher contribution of unmodified part of the substrate to the measured hardness. These results agrees well with literature [42][43][44][45][46]; and hardness decrease with the load is known as the "indentation size effect" (ISE) [47].…”

Section: Hardness Of Nitrided Layersupporting

confidence: 91%

Structural and mechanical properties of radiofrequency N₂/H₂cold plasma-nitrided C38 carbon steel

Bouanis¹,

Bentiss²,

Traisnel³

et al. 2011

Eur. Phys. J. Appl. Phys.

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Abstract.C38 carbon steel has been nitrided by radiofrequency cold plasma discharge with the aim to study the effect of gas composition on structural and mechanical properties of nitrided substrates. The plasma nitriding was carried out on unheated substrates, using two different gas mixtures (75% N 2 /25% H 2 and 25% N 2 /75% H 2 ) for 8 hours of plasma treatment. Electron Probe Microanalysis (EPMA) showed that the nitrogen content and the nitride layer thickness mainly depend on the hydrogen content in the plasma. For 75%N 2 /25%H 2 mixtures, nitrided samples showed the formation of thicker nitride layer with high content of nitrogen compared to those formed in the case of 25% N 2 /75% H 2 or pure N 2 . The thickness of the nitride layer formed is approximately 15 µm for 8 h of plasma with 75% N 2 /25% H 2 . X-ray photoelectron spectroscopy (XPS) was employed to obtain chemical-state information of the plasma nitrided steel surfaces. The mechanical properties of plasma nitrided C38 steel were investigated by Vickers microhardness measurements. The micromechanical results show the formation of a new hard layer on the surface after N 2 /H 2 treatment plasma and it reaches a maximum value of more than 2242 HV 0.005 for 75% N 2 /25% H 2 plasma nitrided samples. However, a decrease in the hardness values with the applied load has been evidenced.

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Section: Hardness Of Nitrided Layersupporting

confidence: 91%

Structural and mechanical properties of radiofrequency N₂/H₂cold plasma-nitrided C38 carbon steel

Bouanis¹,

Bentiss²,

Traisnel³

et al. 2011

Eur. Phys. J. Appl. Phys.

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“…The surface hardness of the nitrided specimens remained practically constant, around 818 HV at a 500 g load. In contrast with 300 HV at the same load in the case of the untreated sample, this means an increment of more than 2.5 times, entailing better results than those obtained by the other authors using plasma nitriding [10,11] or thermochemical treatment of gases nitriding [12]. The reason for this outcome has not been the formation of large nitride precipitates, as pointed out by [8,9].…”

Section: Resultsmentioning

confidence: 95%

Nitriding of 4140 Annealed Low Alloy Steel in RF Plasma

et al. 2013

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The annealed low alloy 4140 steel samples have been nitrided for dierent treatment periods (16 h) in an RF inductive plasma discharge with very low bias voltage (≈ 400 V). The resulting nitrided layer has been observed by means of an optical microscope whereas the nitride phases have been characterised by X-ray analysis. The corrosion response, assessed by the potentiodynamic tests in the 3.5% NaCl solution, presents both higher noble potential values and lower corrosion rates when compared with the untreated sample. The Vickers microhardness tests values show an appreciable increment compared to that of the untreated sample. The process is characterized by a high overall eciency because similar average Vickers tests values were obtained, no matter for how long the treatment was extended. Likewise, the scanning electron micrographs conrmed no appreciable size evolution of the compound layer microstructure at dierent times of treatment.

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“…Bragg's law (2d sin θ = nλ) relates the interplanar distance d measured as d = a hkl /(h 2 + k 2 + l 2 ) 1/2 , where n is an integer referred to as the order of reflection and λ the wavelength of X-ray used, a hkl is the cubic lattice constant and hkl are Miller indices or crystal planes (hkl) of materials [3], which can be determined from XRD data. Equation (2) is used to measure the strain produced in the d-spacing of Al (2 0 0) reflection planes.…”

Section: Residual Stressmentioning

confidence: 99%

“…However, their inadequate surface hardness and wear resistance restrict their applications in fields relating to surface engineering. These surface properties can be improved by exposing samples to nitrogen plasma environment without affecting bulk properties of materials [3,4]. The nitrogen implantation of aluminum and its alloys improves the tribological properties as well as enhances the pitting corrosion and oxidation resistance [5,6].…”

Section: Introductionmentioning

confidence: 99%

Plasma characterization for nitridation of aluminium alloy using 50 Hz ac discharge

Shah

Ahmad

Zakaullah

et al. 2008

Plasma Devices and Operations

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A 50 Hz ac abnormal glow discharge is characterized as a function of filling pressure (1-4 mbar) using a Langmuir probe. It is found that electron temperature, electron density and electron energy distribution function decrease with the gas filling pressure. Nitriding of aluminum alloy (Al−Mg 2 −Si) is performed for various time durations (3, 6, 9 and 12 h) and pressures (1 and 2 mbar) by keeping the input power (100 W) and substrate temperature (250 • C) constant. To explore the surface properties induced by plasma, X-ray diffractometer, optical micrography, atomic force microscopy and Vickers micro-hardness tester diagnostic techniques are used. Results exhibit the formation of cubic aluminum nitride. A significant increase in surface hardness is observed when samples are exposed at 1 mbar pressure for 12 h of processing time. A rapid decrease in surface hardness values with the imposed load suggests the formation of a thin modified surface layer.

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Langmuir probe characterization of nitrogen plasma for surface nitriding of AISI-4140 steel

Cited by 29 publications

References 20 publications

Structural and mechanical properties of radiofrequency N₂/H₂cold plasma-nitrided C38 carbon steel

Structural and mechanical properties of radiofrequency N₂/H₂cold plasma-nitrided C38 carbon steel

Nitriding of 4140 Annealed Low Alloy Steel in RF Plasma

Plasma characterization for nitridation of aluminium alloy using 50 Hz ac discharge

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Langmuir probe characterization of nitrogen plasma for surface nitriding of AISI-4140 steel

Cited by 29 publications

References 20 publications

Structural and mechanical properties of radiofrequency N2/H2cold plasma-nitrided C38 carbon steel

Structural and mechanical properties of radiofrequency N2/H2cold plasma-nitrided C38 carbon steel

Nitriding of 4140 Annealed Low Alloy Steel in RF Plasma

Plasma characterization for nitridation of aluminium alloy using 50 Hz ac discharge

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Product

Resources

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Structural and mechanical properties of radiofrequency N₂/H₂cold plasma-nitrided C38 carbon steel

Structural and mechanical properties of radiofrequency N₂/H₂cold plasma-nitrided C38 carbon steel