Aluminum surface nitriding by an atmospheric-pressure non-thermal plasma technique

2021 ◽  
Author(s):  
zhongyang Ma ◽  
Hongmei Sun ◽  
Huan Zheng ◽  
Yanjun Zhao ◽  
Siyuan Sui ◽  
...  
Keyword(s):  
Plasma Nitriding ◽  
Solidus Temperature ◽  
Surface Hardness ◽  
Nitrogen Plasma ◽  
Aluminum Surface ◽  
Arc Plasma ◽  
N2 Atmosphere ◽  
Excellent Mechanical Property ◽  
Non Thermal Plasma ◽  
N2 Plasma

Abstract The application of aluminum is often limited by low hardness, and plasma nitriding can make it have excellent mechanical property. The purpose of this study is to nitride the aluminum surface by non-thermal transferred arc plasma technology. During the plasma nitriding process, the maximum effective value of output current is about 390 mA and the overall temperature of the samples is much lower than the solidus temperature. It is found that the microstructure and mechanical properties of the aluminum surface are improved by adding hydrogen into the nitrogen plasma. Compared with the surface treated by pure N2 plasma, the particle size of aluminum surface treated by N2/H2 plasma is smaller. The surface hardness of aluminum is nearly doubled after being treated in 6.0 vol%H2 + 94.0 vol%N2 atmosphere.

Simulate the Process of Nitriding Depth on the Surface of Titanium by Mixing Laser and Nitrogen Plasma Nitriding Approach

2013 ◽  
Vol 321-324 ◽  
pp. 305-308
Author(s):  
Guo Jian Zhao
Keyword(s):  
Plasma Nitriding ◽  
Surface Hardness ◽  
Nitrogen Plasma ◽  
Model Description ◽  
Angle Of Incidence ◽  
Scanning Velocity ◽  
Ion Energy ◽  
C Language ◽  
Power Intensity ◽  
Nitrogen Ion

An approach by mixing laser and plasma to conduct nitriding treatment on the surface of titanium can improve the surface hardness, and the hardness of the surface in different nitriding depth is different. We wrote a program, by which we carried out Monte Carlo simulation calculation, in accordance with the model description by C language. In the calculation process, by changing laser power intensity, scanning velocity, nitrogen ion energy and angle of incidence, we got the distribution of nitrogen ions in iron under different conditions, and thus formed computer simulation diagram of titanium nitride process.

Effect of Hydrogen Addition on the Characteristics of Nitrided Martensitic Stainless Steel AISI 420

2016 ◽  
Vol 836 ◽  
pp. 214-218 ◽  
Author(s):  
Istiroyah ◽  
I.N.G. Wardana ◽  
D.J. Santjojo
Keyword(s):  
Diffusion Length ◽  
Plasma Nitriding ◽  
Nitrogen Concentration ◽  
Surface Hardness ◽  
Xrd Analysis ◽  
Nitrogen Plasma ◽  
Pure Nitrogen ◽  
Hydrogen Addition ◽  
Aisi 420 ◽  
And Diffusion

High density RF-DC plasma nitriding was carried out to harden the surface of martensitic stainless steels AISI-420. The nitriding temperature is hold at 673 K (or 400°C). Nitrogen (N2) and mixture of nitrogen (N2)-hydrogen (H2) was utilized as a plasma atmosphere. Vickers micro-hardness testing was utilized to examine the change of surface hardness and the corresponding microstructure analysis was carried out by utilizing X-Ray Diffraction (XRD) analysis. Nitrogen concentration and diffusion length were characterized by using Auger Electron Spectroscopy (AES). Hydrogen addition to nitrogen plasma resulted significant increase of hardness, nitrogen concentration and diffusion length compared to pure nitrogen plasma. The significant peak shift observed in XRD pattern of specimen nitrided with N2+H2 plasma indicates new phase formation or phase transformation. Those phenomena related to hydrogen role in nitriding process.

scholarly journals Acceleration of Plasma Nitriding at 550 °C with Rare Earth on the Surface of 38CrMoAl Steel

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1122
Author(s):  
Dongjing Liu ◽  
Yuan You ◽  
Mufu Yan ◽  
Hongtao Chen ◽  
Rui Li ◽  
...  
Keyword(s):  
Rare Earth ◽  
Electron Microscope ◽  
Weight Gain ◽  
Plasma Nitriding ◽  
Nitrided Layer ◽  
Surface Hardness ◽  
Optical Microscope ◽  
Steel Microstructure ◽  
Transmission Electron ◽  
Modified Layer

In order to explore the effect of the addition of rare earth (RE) to a steel microstructure and the consequent performance of a nitrided layer, plasma nitriding was carried out on 38CrMoAl steel in an atmosphere of NH3 at 550 °C for 4, 8, and 12 h. The modified layers were characterized using an optical microscope (OM), a microhardness tester, X-ray diffraction (XRD), a scanning electron microscope (SEM), a transmission electron microscope (TEM), and an electrochemical workstation. After 12 h of nitriding without RE, the modified layer thickness was 355.90 μm, the weight gain was 3.75 mg/cm2, and the surface hardness was 882.5 HV0.05. After 12 h of RE nitriding, the thickness of the modified layer was 390.8 μm, the weight gain was 3.87 mg/cm2, and the surface hardness was 1027 HV0.05. Compared with nitriding without RE, the ε-Fe2-3N diffraction peak was enhanced in the RE nitriding layer. After 12 h of RE nitriding, La, LaFeO3, and a trace amount of Fe2O3 appeared. The corrosion rate of the modified layer was at its lowest (15.089 × 10−2 mm/a), as was the current density (1.282 × 10−5 A/cm2); therefore, the corrosion resistance improved.

EFFECT OF NITROGEN AMOUNT ON TRIBOLOGICAL BEHAVIOR OF PLASMA NITRIDED 31CrMoV9 STEEL

2019 ◽  
Vol 26 (07) ◽  
pp. 1850217 ◽  
Author(s):  
O. ÇOMAKLI ◽  
A. F. YETIM ◽  
B. KARACA ◽  
A. ÇELIK
Keyword(s):  
Wear Resistance ◽  
Tribological Behavior ◽  
Wear Behavior ◽  
Plasma Nitriding ◽  
Surface Hardness ◽  
Compound Layer ◽  
Gas Mixture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pin On Disk

The 31CrMoV9 steels were plasma nitrided under different gas mixture ratios to investigate an influence of nitrogen amount on wear behavior. The structure, mechanical and tribological behavior of untreated and nitrided 31CrMoV9 steels were analyzed with X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), microhardness device, 3D profilometer and pin-on-disk wear tester. The analysis outcomes displayed that the compound layer consists of nitride phases (Fe2N, Fe3N, Fe4N and CrN). Additionally, the thickness of the compound layers, surface hardness and roughness increased with increasing nitrogen amount in the gas mixture. The highest friction coefficient value was obtained at nitrogen amount of 50%, but the lowest value was seen at nitrogen amount of 6%. It was observed that wear resistance of 31CrMoV9 steel improved after plasma nitriding, and the best wear resistance was also obtained from plasma nitrided sample at the gas mixture of 94% H[Formula: see text]% N2.

Arc plasma nitriding of low carbon steel

2001 ◽  
Vol 145 (1-3) ◽  
pp. 24-30 ◽  
Author(s):  
S.C. Mishra ◽  
B.C. Mohanty ◽  
B.B. Nayak
Keyword(s):  
Carbon Steel ◽  
Plasma Nitriding ◽  
Low Carbon Steel ◽  
Arc Plasma ◽  
Low Carbon

scholarly journals Effects of Surface Modification by Means of Low-Temperature Plasma Nitriding on Wetting and Corrosion Behavior of Austenitic Stainless Steel

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 98 ◽  
Author(s):  
Francesca Borgioli ◽  
Emanuele Galvanetto ◽  
Tiberio Bacci
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Corrosion Resistance ◽  
Low Temperature ◽  
Surface Morphology ◽  
Corrosion Behavior ◽  
Sessile Drop ◽  
Plasma Nitriding ◽  
Surface Hardness ◽  
Temperature Plasma

Low-temperature nitriding of austenitic stainless steels produces modified surface layers, consisting mainly of the S phase, which improve surface hardness and corrosion resistance. Because of the localized plastic deformations, owing to modified layer formation, and ion bombardment occurring during the process itself, this treatment produces also modifications of surface morphology and roughness, which can affect wettability and corrosion behavior. In this study the effects of plasma nitriding, performed using different treatment conditions, on the surface morphology and roughness, and thus on wettability and corrosion resistance, of AISI 202 specimens with different initial finishings (2D and polished finishing) were investigated. Different probe liquids, having both high (bi-distilled water and solution of 3.5% NaCl) and low (ethanol and rapeseed oil) surface tension, were employed for assessing the wetting behavior with the sessile drop method. The contact angle values for water increased markedly when nitriding was performed on polished samples, while this increase was smaller for 2D samples, and on selected specimens a hydrophobic behavior was observed. Very low contact angle values were registered using low surface tension liquids, suggesting an oleophilic behavior. Corrosion resistance in a 5% NaCl solution was assessed, and it depended on the characteristics of the nitrided specimens.

scholarly journals X-Ray Phase Analysis Of Nitrided Layers Of X2CrNiMo17-12-2 Austenitic Steel

2015 ◽  
Vol 60 (3) ◽  
pp. 2005-2012 ◽  
Author(s):  
T. Frączek ◽  
M. Olejnik ◽  
M. Pilarska
Keyword(s):  
Austenitic Steel ◽  
Phase Analysis ◽  
Plasma Nitriding ◽  
Subsurface Layer ◽  
Nitrogen Plasma ◽  
Nitriding Process ◽  
X Ray ◽  
Temperature Range ◽  
Chromium Nitrides

Abstract This work presents the results of diffraction analyses carried out using X-ray phase analyses (XRD and GIXRD) of nitrided layers of X2CrNiMo17-12-2 austenitic steel. Plasma nitriding process was c arried out in the temperature range of 325 ÷ 400 °C and time of 2 ÷ 4 h. Hydrogen-nitrogen plasma was used as reactive atmosphere (H2 75% + N2 25%) with pressure of 150 Pa. On the basis of the X-ray analyses it was stated that the obtained nitrided layers consisted of a subsurface layer of chromium nitrides and a zone of nitrogen saturated austenite.

Ti6Al4V Surface Hardness Improvement by Duplex Coating

2013 ◽  
Vol 701 ◽  
pp. 370-374
Author(s):  
Yusliza Yusuf ◽  
Zulkifli Mohd Rosli ◽  
Jariah Mohamad Juoi ◽  
Zainab Mahamud ◽  
Kwan Wai Loon
Keyword(s):  
Microwave Plasma ◽  
Plasma Nitriding ◽  
Microstructural Analysis ◽  
Surface Hardness ◽  
Hardness Measurement ◽  
Compound Layer ◽  
Ti6al4v Alloy ◽  
Process Time ◽  
Wear Properties ◽  
Duplex Coating

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.

scholarly journals Characterization of opportunity for upgrading of the system based on arc plasma torch for thermal spaying of ceramic materials, by means of use of fuel vortex intensifier. Part I: Thermodynamic modeling of the system efficiency parameters

2021 ◽  
Vol 66 (4) ◽  
pp. 399-410
Author(s):  
O. G. Devoino ◽  
A. V. Gorbunov ◽  
V. A. Gorbunova ◽  
A. S. Volod’ko ◽  
V. A. Koval ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Plasma Torch ◽  
Ceramic Powder ◽  
Ceramic Coatings ◽  
Powder Materials ◽  
Arc Plasma ◽  
Liquefied Petroleum Gas ◽  
Functional Coatings ◽  
Arc Plasma Torch ◽  
N2 Plasma

One of the main trends in the field of improving the modern technologies of thermal spraying, including plasma one, for functional ceramic coatings formation is the reducing the energy consumption of the process. In this regard, one of the important directions for improving these technologies is the development of their new versions, using the principle of adding inexpensive fuel-oxidizer mixtures based on hydrocarbons with air. This type of plasma-fuel type of spraying will be promising for application at the present time, first of all, in order to obtain refractory functional coatings. For this purpose, we investigated the opportunity for upgrading an industrial unit/system for plasma spraying of ceramic powder materials with arc plasma torch of 25–40 kW power by the use of experimental variant of a fuel gas-vortex intensifier. The thermodynamic assessment of possible parameters of the generated mixed flow after the torch with this fuel intensifier was carried out to estimate the applicability of this system to optimize the spraying of oxide and carbide coatings (based on the examples of Al2O3, Cr3C2 and other powders). The analysis of possible parameters of the produced flow after the torch with intensifier was performed for the cases of main C–H–O–N–Ar–Me (Me = Al, Cr) systems and additional C–H–O–Al-system to assess the potential of this system to modify the technology of oxide and carbide ceramic coatings formation. New regimes, which were analyzed in our research as the simulants of Al2O3 spraying, surpass on calculated energy efficiency characteristics (by 10–20 %) one of the new prospective spraying methods with (СO2+СH4)-plasma, as well as the conventional method of powder heating during the spraying with N2-plasma. The case of our proposed fuel assisted process (FA-APS) with liquefied petroleum gas (LPG) fuel for the heating of ceramic powders (especially, Al2O3) demonstrates the advantage of the process (in particular, on the energy efficiencies and energy consumption) in a comparison with the conventional regimes of APS of the powders (in N2 plasma of the standard torch). For the variants of the FA-APS with Al2O3 and Cr3C2 feedstock powders it was established to be potentially possible to obtain (at the moderate values of total electric energy consumption for the torch and auxiliary equipment, – near 1.8 and 1.0 kWh/(kg of product)) such high level of the process productivity on the final product as approximately 17 and 28 kg/h, respectively; at the values of required power of the torch:  28.2 and  22.3 kW.

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