TEM analysis of surface layer of Ti-6Al-4V ELI alloy after slide burnishing and low-temperature gas nitriding

2021 ◽

Author(s):

Xiangzhen Zhu ◽

Fuchu Liu ◽

Shihao Wang ◽

Shouxun Ji

Keyword(s):

Heat Treatment ◽

Low Temperature ◽

Mechanical Test ◽

Equilibrium Phase ◽

Solution Temperature ◽

Tem Analysis ◽

Die Cast ◽

Zn Concentration ◽

Temperature Heat ◽

Cast Alloys

AbstractIn the present work, a novel low-temperature heat-treatable recycled die-cast Al–Mg alloy was developed by adding Zn into non-heat-treatable Al–5Mg–1.5Fe–0.5Mn alloy. The results showed that Zn additions resulted in the formation of equilibrium phase T-Mg32(Al, Zn)49 under as-cast condition, which can be dissolved into the α-Al matrix at a relatively low solution temperature (430 °C) and thus set the base for the low-temperature heat treatment. The mechanical test results indicated that Zn additions had a smooth liner improvement in the strength of all as-cast alloys and T6-state alloys with 1% and 2% Zn as its concentration increased but resulted in a sharp improvement on the strength of T6-state alloy when Zn concentration increased from 2 to 3%. TEM analysis revealed that the precipitate in T6-state Al–5Mg–1.5Fe–0.5Mn–3Zn alloy is η′ phase, rather than the widely reported T″ or T′ phase in other Al–Mg–Zn alloys with approximately same Mg and Zn concentrations. After the optimized low-temperature T6 heat treatment (solution at 430 °C for 60 min and ageing at 120 °C for 16 h), the Al–5Mg–1.5Fe–0.5Mn–3Zn alloy exhibits the yield strength of 321 MPa, ultimate tensile strength of 445 MPa and elongation of 6.2%.

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Low-temperature gas nitriding of AISI 4140 steel accelerated by LaFeO3 perovskite oxide

Applied Surface Science ◽

10.1016/j.apsusc.2018.10.111 ◽

2019 ◽

Vol 466 ◽

pp. 989-999 ◽

Cited By ~ 5

Author(s):

Xing Chen ◽

Xiangyun Bao ◽

Yang Xiao ◽

Chengsong Zhang ◽

Lina Tang ◽

...

Keyword(s):

Low Temperature ◽

Perovskite Oxide ◽

Aisi 4140 Steel ◽

Gas Nitriding ◽

Aisi 4140

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THE INFLUENCE OF THE SOAKING TEMPERATURE OF NITRIDED WCL TOOL STEEL (EN-X37CrMoV5-1) ON THE MICROHARDNESS AND TRIBOLOGICAL WEAR OF THE SURFACE LAYER

Tribologia ◽

10.5604/01.3001.0010.6983 ◽

2016 ◽

Vol 268 (4) ◽

pp. 69-78

Author(s):

Michał DWORAK ◽

Adrian BARYLSKI ◽

Krzysztof ANIOŁEK ◽

Elizaveta STEPANOVA

Keyword(s):

Surface Layer ◽

High Temperature ◽

Low Temperature ◽

Tool Steel ◽

Nitrided Layer ◽

Industrial Furnace ◽

Tribological Tests ◽

Nitrided Steel ◽

Hot Work Tool Steel ◽

Soaking Temperature

The present paper refers to the evaluation of the influence of soaking temperature of nitrided hot work tool steel, X37CrMoV5-1 (WCL), intended for dies for extruding aluminium profiles, on the structure, microhardness, and tribological wear of the nitrided layer. The research involved nitrided steel specimens (X37CrMoV5-1) soaked for 8 hours in an industrial furnace at temperatures of 450°C, 480°C, 520°C, 560°C, and 600°C. For comparison purposes, a REFERENCES material was used, which was not soaked after nitriding. Initially, as the soaking temperature raised, the microhardness of the nitrided layer increased by ca. 10%; however, a further increase in the soaking temperature to more than 450°C caused a decrease in the microhardness of the nitrided layer. The results of tribological tests showed that soaking nitrided steel at a low temperature (450°C) and high temperature (600°C) caused a decrease in tribological wear. Out of the tested materials, the highest microhardness of the upper layer was observed in the samples soaked at 450°C, while the highest resistance to tribological wear was obtained for the samples soaked at 600°C. The conducted tests indicate the possibility of extending the lifetime of dies made from the investigated nitrided steel.

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The laboratory tests of hybrid layers combining hardfacing and nitriding dedicated to increase the durability of forging tools in hot forging processes

Welding Technology Review ◽

10.26628/wtr.v91i2.1020 ◽

2019 ◽

Vol 91 (2) ◽

Cited By ~ 2

Author(s):

Paweł Widomski ◽

Zbigniew Gronostajski ◽

Marcin Kaszuba ◽

Jagoda Kowalska ◽

Mariusz Pawełczyk

Keyword(s):

Surface Layer ◽

Chemical Composition ◽

Laboratory Tests ◽

Hot Forging ◽

Composition Analysis ◽

Wear Resistant ◽

Gas Nitriding ◽

Use Wear ◽

Different Types ◽

Hybrid Layers

In response to the growing need to use wear-resistant layers that increase durability of tools in forging pro-cesses, hybrid layers have been proposed that combine hardfacing with nitriding treatment. This article presents the results of laboratory tests of surface wear-resistant layers made with a new hybrid technology Gas-Shielded Metal Arc surfacing (hardfacing) with ZeroFlow gas nitriding. Specimens made with hardfacing or nitriding were prepared and examined. Analysis covered the thorough microstructure study, EDX chemical composition analysis and microhardness analysis. In experiment, 3 different types of nitrided layers were proposed for alpha, gamma prim and epsilon nitrides in the surface layer. The results of metallographic research in the surface layer was presented. The analysis of chemical composition in the particular overlay welds was performed to determine the content of alloying elements in the particular overlay welds. The susceptibility to nitriding of used weld materials as well as the ability to form particular types of nitrides on selected welded substrates was also tested.

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Facile Preparation of Ni2 P with a Sulfur-Containing Surface Layer by Low-Temperature Reduction of Ni2 P2 S6

Angewandte Chemie ◽

10.1002/ange.201510599 ◽

2016 ◽

Vol 128 (12) ◽

pp. 4098-4102 ◽

Cited By ~ 7

Author(s):

Song Tian ◽

Xiang Li ◽

Anjie Wang ◽

Roel Prins ◽

Yongying Chen ◽

...

Keyword(s):

Surface Layer ◽

Low Temperature ◽

Temperature Reduction ◽

Facile Preparation ◽

Sulfur Containing ◽

Low Temperature Reduction

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Effect of Adjusted Gas Nitriding Parameters on Microstructure and Wear Resistance of HVOF-Sprayed AISI 316L Coatings

Materials ◽

10.3390/ma12111760 ◽

2019 ◽

Vol 12 (11) ◽

pp. 1760 ◽

Cited By ~ 5

Author(s):

Pia Kutschmann ◽

Thomas Lindner ◽

Kristian Börner ◽

Ulrich Reese ◽

Thomas Lampke

Keyword(s):

Wear Resistance ◽

Low Temperature ◽

Process Management ◽

Surface Activation ◽

Aisi 316L ◽

Spray Coatings ◽

Gas Nitriding ◽

Surface Distance ◽

Diffusion Depth ◽

Sprayed Coating

Gas nitriding is known as a convenient process to improve the wear resistance of steel components. A precipitation-free hardening by low-temperature processes is established to retain the good corrosion resistance of stainless steel. In cases of thermal spray coatings, the interstitial solvation is achieved without an additional surface activation step. The open porosity permits the penetration of the donator media and leads to a structural diffusion. An inhomogeneous diffusion enrichment occurs at the single spray particle edges within the coating’s microstructure. A decreasing diffusion depth is found with increasing surface distance. The present study investigates an adjusted process management for low-temperature gas nitriding of high velocity oxy-fuel-sprayed AISI 316L coatings. To maintain a homogeneous diffusion depth within the coating, a pressure modulation during the process is studied. Additionally, the use of cracked gas as donator is examined. The process management is designed without an additional surface activation step. Regardless of surface distance, microstructural investigations reveal a homogeneous diffusion depth by a reduced processing time. The constant hardening depth allows a reliable prediction of the coatings’ properties. An enhanced hardness and improved wear resistance is found in comparison with the as-sprayed coating condition.

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