Investigation of nitrogen ionization state and its effect on the nitride layer during fiber laser gas nitriding of Ti-6Al-4V alloy

2021 ◽  
pp. 127254
Author(s):  
Jinchang Guo ◽  
Yu Shi ◽  
Chunkai Li ◽  
Gang Zhang
Keyword(s):  
Fiber Laser ◽  
Nitride Layer ◽  
Ionization State ◽  
Gas Nitriding

Hard-Ceramic Layer Formed on Ti-29Nb-13Ta-4.6Zr and Ti-6Al-4V ELI during Gas Nitriding

2007 ◽  
Vol 561-565 ◽  
pp. 1509-1512 ◽  
Author(s):  
Masaaki Nakai ◽  
Mitsuo Niinomi ◽  
Toshikazu Akahori ◽  
Naofumi Ohtsu ◽  
H. Nishimura ◽  
...  
Keyword(s):  
Vickers Hardness ◽  
Photoelectron Spectroscopy ◽  
Hardness Measurement ◽  
Nitride Layer ◽  
Titanium Nitrides ◽  
Oxygen Impurity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gas Nitriding ◽  
Biomedical Titanium Alloy

The surface of Ti-29Nb-13Ta-4.6Zr (TNTZ) subjected to gas nitriding at 1023–1223 K was investigated in comparison with the conventional biomedical titanium alloy, Ti-6Al-4V ELI (Ti64). After gas nitriding, the microstructures near the surface of these alloys were observed by optical microscopy, X-ray diffraction, Auger electron spectroscopy, and X-ray photoelectron spectroscopy. In both alloys, two titanium nitrides (TiN and Ti2N) are formed and the α phase precipitated by gas nitriding. Furthermore, oxygen impurity in the gas nitriding atmosphere reacts with the titanium nitrides; thus, TiO2 is formed at the outermost titanium nitride layer. The surface hardening was also evaluated by Vickers hardness measurement. The Vickers hardness near the surface of TNTZ and Ti64 increases significantly by gas nitriding.

Die Soldering Phenomenon on the H13 Tool Steel with Shot Peening and Nitriding Surface Treatment

2015 ◽  
Vol 1101 ◽  
pp. 157-163
Author(s):  
Myrna Ariati ◽  
Dwi Marta Nurjaya ◽  
Rizki Aldila
Keyword(s):  
Surface Treatment ◽  
Tool Steel ◽  
Shot Peening ◽  
Surface Hardness ◽  
Nitride Layer ◽  
H13 Steel ◽  
Gas Nitriding ◽  
Aisi H13 Steel ◽  
H13 Tool Steel ◽  
Aisi H13

Die soldering occurs when molten aluminum sticks to the surface of a die material and remains there after the ejection of the part. This resulted in low productivity and economic value in the foundry industry. Nitriding surface treatment is considered as an effective way in enhancing the service life of AISI H13 steel dies and to prevent soldering effect. The focus of this paper is to investigate the influence of three different surface conditions in terms of roughness, gas nitriding and pretreatment prior to gas nitriding on the soldering effect. Three kind of samples made of AISI H13 steel were pretreated (quenched and tempered) and followed by : shot peened, gas nitrided and shot peening followed by gas nitriding, were immersed in liquid melted ADC 12 Aluminium alloy at 30 seconds, 30 minutes, 2 hours and 5 hours, at a constant temperature of 680oC in a holding furnace. Characterizations on the surface of the steel were focused on the optical microstructure, microhardness profile, FE SEM observation and enegy dispersive spectrometry mapping. It was found that shot peening prior to nitriding gives a higher surface hardness and depth of nitride layer of H13 tool steel, 1140 HV (>70 HRC) and 120.5 μm, than the nitriding only process, 1033 HV (68 HRC) and 105 μm. The higher the hardness and depth of nitride layer expected would reduce the die soldering effect at the surface of the H13 tool steel dies. It was also found that the only shot peening treatment resulted in a tendency of soldering accompanied by the formation of intermetallic layers ; while soldering is not found on the nitrided and shot peened-nitrided samples.

A Comparison of Gas Nitriding and Laser Nitriding on Industrial Pure Iron and Ti-Induced Iron

2018 ◽  
Vol 934 ◽  
pp. 79-88 ◽  
Author(s):  
An Min Liu ◽  
Yu Fan ◽  
Pei Zhi Li ◽  
Kun Chen ◽  
Ke Pu ◽  
...  
Keyword(s):  
Pure Iron ◽  
Laser Power ◽  
Metal Layer ◽  
Nitrogen Compound ◽  
Surface Hardness ◽  
Nitride Layer ◽  
Nitrogen Compounds ◽  
Laser Nitriding ◽  
Gas Nitriding ◽  
The Difference

Overview of Gas nitriding on the surface of industrial pure iron and laser gas nitriding, research under different nitriding process, the phase, organization and mechanical properties of the nitride layer that is the difference. Plasma sprayed titanium on industrial pure iron surface, the laser nitriding experiments were carried out on the titanium surface. The formation of iron and nitrogen compounds is induced by the combination of titanium nitride. The difference between gas nitriding and laser nitriding is analyzed. The results show that: (1) after gas nitriding, the nitrides formed on the surface of pure iron are mainly ε-Fe2-3N and γ′-Fe4N, the surface hardness is 158 HV, and the increase is 32%. (2) in the 500 W laser power, laser nitriding formed on the surface of Titanium metal layer of pure iron, but not the formation of iron and nitrogen compound, the surface hardness of 168 HV, increased by 46%. (3) under the condition of 500 W laser power, the industrial pure iron was nitrided by laser, without the formation of iron and nitrogen compounds, but the surface hardness of the sample was increased by 20%.

scholarly journals Structure and properties of the modified diffusion nitride-oxide surface layer

2021 ◽  
Vol 264 ◽  
pp. 05054
Author(s):  
Kholikul Eshkabilov ◽  
Sherzod Berdiyev
Keyword(s):  
Surface Layer ◽  
Water Vapor ◽  
Oxide Layer ◽  
Nitride Layer ◽  
Phase Changes ◽  
Oxide Surface ◽  
Gas Nitriding ◽  
Modified Surface ◽  
Nitride Oxide ◽  
Nitride Zone

To combine the processes of gas nitriding and oxidation in water vapor, the effects of the atmospheric nitrogen potential in dissociated ammonia on the formation of surface diffusion nitride phases are studied. Modification of the surface nitride layer with oxygen was carried out by oxidation of the nitride zone at the second stage of obtaining an oxycarbonitride layer. The corrosion and wear-resistant properties of the nitride-oxide layer t of the lowest nitride layer are investigated, depending on the phase changes in the nitride layer after oxidation. The distributions of the elements in the nitride-oxide layer are determined, and the nature of the formation of the modified surface layer under the combination of gas nitriding with subsequent oxidation in water vapor is established.

118 Effect of Alloying Elements on Nitride Layer Formation in Aluminum Alloys by Gas Nitriding

2010 ◽  
Vol 2010.18 (0) ◽  
pp. _118-1_-_118-3_
Author(s):  
Masashi YOSHIDA ◽  
Masahiro OKUMIYA ◽  
Noah UTSUMI ◽  
Yoshiki TSUNEKAWA
Keyword(s):  
Aluminum Alloys ◽  
Nitride Layer ◽  
Alloying Elements ◽  
Layer Formation ◽  
Gas Nitriding ◽  
Effect Of Alloying

Ultrasonic Nano-Crystal Surface Modification Assisted Gas Nitriding of Ti6Al4V Alloy

2017 ◽  
Author(s):  
Jun Liu ◽  
Zhencheng Ren ◽  
Chi Ma ◽  
Yalin Dong ◽  
Chang Ye
Keyword(s):  
Surface Modification ◽  
Crystal Surface ◽  
Nitrogen Adsorption ◽  
Fold Increase ◽  
Compound Layer ◽  
Nitride Layer ◽  
Ti6al4v Alloy ◽  
Gas Nitriding ◽  
Treated Sample ◽  
Reaction Capability

The effects of Ultrasonic Nanocrystal Surface Modification (UNSM) on the gas nitriding of Ti6Al4V alloy has been investigated. The gas nitriding was performed at 700 and 800 °C. The microstructure after UNSM and gas nitriding was characterized using X-ray diffraction and scanning electron microscopy. Microstructural investigations revealed the formation of an approximately 10 μm thick severe plastic deformation (SPD) layer after UNSM treatment. After nitriding at 700 °C and 800 °C, a compound layer consisting of an approximately 0.2 μm and 1.9 μm thick nitride layer was observed in UNSM-treated Ti6Al4V alloy, which exhibits a nearly two-fold increase in nitride layer thickness as compared with the un-treated sample. This suggests that the nitrogen adsorption and the reaction capability are enhanced in the UNSM-treated Ti6Al4V alloy. This enhancement can be attributed to the high density dislocations and grain boundaries introduced by UNSM that serve as efficient diffusivity channels for interstitial gaseous atoms.

Structural Characterization of Titanium Nitride Coatings on AISI M2 Steel

2007 ◽  
Vol 554 ◽  
pp. 219-224 ◽  
Author(s):  
G. Deniz ◽  
Şaduman Şen ◽  
Uğur Şen
Keyword(s):  
Titanium Nitride ◽  
Structural Characterization ◽  
Treatment Time ◽  
Deposition Process ◽  
Xrd Analysis ◽  
Nitride Layer ◽  
Gas Nitriding ◽  
Process Gas ◽  
Nitride Layers

In this work, some surface properties of AISI M2 steel were improved by a thermoreactive deposition process. Gas nitriding was realized on AISI M2 steel at 550°C for 2 h in an ammoniac atmosphere and then, titanizing treatment performed on pre-nitrided steel in the powder mixture consisting of ferro-titanium, ammonium chloride and alumina at 1000°C for 1-4 h. Structural characterization of titanium nitride layer formed on the surface of AISI M2 steel was carried out by using optical microscopy, scanning electron microscopy, electron microprobe and Xray diffraction (XRD) analysis. The hardness measurements of titanium nitride layer were conducted under 10 g loads by using Vickers microhardness indenter. Structural analysis studies showed that titanium nitride layers formed on the AISI M2 steel samples were smooth, compact and homogeneous. XRD analysis show that the coating layer formed on the steel samples includes TiN, Fe6Mo7N2, C0.7N0.3Ti, C0.3N0.7Ti and V2N phases. The hardness of titanium nitride layers formed on the steel samples is between 2040±186 and 2418±291 HV0.01. The thickness of titanium nitride layer formed on the steel samples ranged from 3.86±0.43 9m to 6.13±0.47 9m, depending on treatment time.

scholarly journals The Effect of Laser Nitriding on Surface Characteristics and Wear Resistance of NiTi Alloy with Low Power Fiber Laser

2021 ◽  
Vol 11 (2) ◽  
pp. 515
Author(s):  
Hao Wang ◽  
Ralf Nett ◽  
Evgeny L. Gurevich ◽  
Andreas Ostendorf
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Low Power ◽  
Fiber Laser ◽  
Niti Alloy ◽  
Nitride Layer ◽  
Wear Testing ◽  
Wear Loss ◽  
Laser Nitriding

The laser nitriding was performed in nitrogen gas at room temperature (20 °C) and low temperature (−190 °C) by a low power fiber laser to modify the wear and abrasion resistance of NiTi alloy. The surface roughness and element composition were analyzed by roughness device and energy-dispersive X-ray spectroscopy respectively. The results of roughness show that laser treatment can change the surface roughness due to the laser remelting. The effect of laser nitriding on the microhardness, friction coefficient, and worn scars of NiTi alloy was also studied, which shows that the microhardness of the NiTi alloy increases after laser nitriding. The optical microscope and scanning electron microscope were used to characterize the surface of NiTi alloy after wear testing to observe the microstructure of worn scars. The results show that the laser nitriding with different parameters can induce a nitride layer with different thicknesses and the higher energy deposition is the key factor for the formation of the nitride layer, which can decrease the friction coefficient and reduce wear loss during the application of NiTi alloy. The improvement of wear resistance can be attributed to the hard nitriding layer.

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