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Wear Resistance and Non-Magnetic Layer Formation on 316L Implant Material with plasma nitriding

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Journal of Bionic Engineering 2014年第4期11卷 620-629页

作者： Ali Fatih Yetim Mustafa Yazici Department of Mechanical Engineering Faculty of Engineering and Architecture Erzurum Technical University Erzurum 25700 Turkey Department of Nanoscience and Nanoengineering Ataturk University Erzurum 25240 Turkey

In this study, the applicability of plasma nitriding treatment in the production of non-magnetic and corrosion resistant layer on 316L stainless steel implant material was investigated. 316L stainless steel substrates were plasma nitrided at temperatures of 350 ℃, 375 ℃, 400 ℃, 425 ℃ and 450 ℃ for 2 h in a gas mixture of 50% N2-50% H2, respectively. It was determined that the treatment temperature is the most important factor on the properties of the corrosion resistant layer of 316L stainless steel. The results show that s-phase formed at the temperatures under 400 ℃, and at the temperatures above 400 ℃, instead of s-phase, CrN and y＇-Fe4N phases were observed in the modified layer. The electrical resistivity and surface roughness of the modified layer increase with treatment temperature. Under 400 ℃ the corrosion resistance increased with the temperature, above 400 ℃ it decreased with the increase in treatment temperature. It was analyzed that the electrical resistivity and the soft （ideal） ferro- magnetic properties of 316L stainless steel increased with treatment temperature during nitriding treatment. Also, plasma ni- triding at low temperatures provided magnetic behavior close to the ideal untreated 316L stainless steel.

关键词： 316L stainless steel biomaterials plasma nitriding magnetic properties wear electrical resistivity

Glow Discharge plasma nitriding of AISI 304 Stainless Steel

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plasma Science and Technology 2007年第4期9卷 463-468页

作者： A.QAYYUM M.A.NAVEED S.ZEB G.MURTAZA M.ZAKAULLAH National Tokamak Fusion Program IslamabadPakistan Department of Physics Quaid-i-Azam University45320 IslamabadPakistan Salam Chair in Physics Government College University54000 LahorePakistan

Glow discharge plasma nitriding of AISI 304 austenitic stainless steel has been carried out for different processing time under optimum discharge conditions established by spectroscopic analysis. The treated samples were analysed by X-ray diffraction （XRD） to explore the changes induced in the crystallographic structure. The XRD pattern confirmed the formation of an expanded austenite phase （TN） owing to incorporation of nitrogen as an interstitial solid solution in the iron lattice. A Vickers microhardness tester was used to evaluate the surface hardness as a function of indentation depth （μm）. The results showed clear evidence of surface changes with substantial increase in surface hardness.

关键词： optical diagnostics plasma nitriding austenitic stainless steel

Microstructure and Wear Resistance of in situ Formed Duplex Coating Fabricated by plasma nitriding Ti Coated 2024 Al Alloy

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Journal of Materials Science & Technology 2014年第12期30卷 1278-1283页

作者： Fanyong Zhang Mufu Yan National Key Laboratory for Precision Hot Processing of Metals School of Materials Science and EngineeringHarbin Institute of Technology

In this study, plasma nitriding was carried out on pure titanium film coated 2024 Al alloy to improve its surface mechanical property. Ti film with the thickness of 3.0 mm was firstly fabricated by means of magnetron sputtering method. Then, the Ti coated specimen was subjected to plasma atmosphere comprising 40% N2e60% H2 at 430 C for 8 h. The microstructures of the nitrided specimens were characterized by X-ray diffraction and scanning electron microscopy. Microhardness tester and pin-on-disc tribometer were used to test the mechanical properties of the untreated and nitrided specimen. The results showed that the surface of the nitrided specimen was composed of three layers（i.e. the outside nitride Ti N0.3layer, the middle Al3 Ti layer and the inside Al18Ti2Mg3 layer）. The surface hardness and wear resistance of 2024 Al alloy were increased simultaneously by duplex treatment. The untreated specimen exhibited severe adhesive wear while the nitrided one behaved in middle abrasive wear.

关键词： Aluminum alloy plasma nitriding Wear behavior Diffusion coating Wear

Examination of plasma nitriding Microstructure with Addition of Rare Earths

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Journal of Rare Earths 2004年第2期22卷 272-276页

作者：张津 Department of Materials Science and Engineering Chongqing Institute of Technology Chongqing 400050 China

Medium-carbon alloy steel was plasma nitrided with rare earths La, Ce and Nd into the nitriding chamber respectively. The nitriding layer microstructures with and without rare earths were compared using optical microscope,normal SEM and high resolution SEM, as well as TEM. It was found that the extent of the influence on plasma nitriding varies with different contents of rare earth. The effect of plasma nitriding is benefit from adding of Ce or Nd. The formation of hard and brittle phase Fe_(2-3)N can be prevented and the butterfly-like structure can be improved by adding Ce or Nd. However, pure La may prevent the diffusion of nitrogen and the formation of iron nitride, and reduce the depth of diffusion layer.

关键词： metal materials plasma nitriding microstructure rare earths

Surface modification of plasma nitriding on AlxCoCrFeNi high-entropy alloys

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Journal of Materials Science & Technology 2020年第13期47卷 140-145页

作者： Jinxiong Hou Wenwen Song Liwei Lan Junwei Qiao College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan030024China Steel Institute RWTH Aachen UniversityAachen52072Germany Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of EducationTaiyuan University of TechnologyTaiyuan030024China

plasma nitriding is successfully employed in treating AlxCoCrFeNi high-entropy alloys(HEAs)with finelydivided Al content(i.e.,x values in molar ratio,x=0.1-0.8)to develop wear-resistant structural *** greatly removes the Al from the matrix that completely deplete the Ni-Al enriched phase,forming nanoscaled nitrides(AIN and CrN)precipitations near the *** promotes the hardness of present alloys with values widely ranging from 276 HV to 722 ***,the higher content the Al,the smaller thickness the nitrides layer,but the higher hardness due to the increased amount of hard nitrides phases and volume fraction of BCC ***,plasma nitriding considerably improves the wear re sistance of AlxCoCrFeNi HEAs by 4-18 times.

关键词： plasma nitriding High-entropy alloy Microstructure Hardness Wear and tribology

Surface Properties of Fe_4N Compounds Layer on AISI 4340 Steel Modified by Pulsed plasma nitriding

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Journal of Materials Science & Technology 2013年第3期29卷 287-290页

作者： J.C.Díaz-Guillén G.Vargas-Gutiérrez E.E.Granda-Gutiérrez J.S.Zamarripa-Pia S.I.Pérez-Aguilar J.Candelas-Ramírez L.lvarez-Contreras Centro de Investigacin en Materiales Avanzados S.C.Miguel de Cervantes 120Complejo Industrial ChihuahuaC.P.31109 ChihuahuaChihuahuaMexico Corporacin Mexicana de Investigacin en Materiales S.A.de C.V.Ciencia y Tecnología No 790Fracc.Saltillo 400C.P.25290 SaltilloCoahuilaMexico Centro de Investigacin y Estudios Avanzados del IPN Unidad SaltilloCarretera Saltillo Monterrey km 13Apdo.Postal 663C.P.25000 SaltilloCoahuilaMexico

In this work, the effect of nitriding current density on hardness, crystalline phase composition, layer thickness and corrosion rate of AlSl 4340 steel has been studied. X-ray diffraction analysis shows that thin layers formed during nitriding process are constituted of 7-Fe4N for samples processed between 1 and 2.5 mA/cm2. Thickness of nitrided layer increases proportionally to current density （0 μm for 0.5 mA/cm2 to 15 pm for 2.5 mA/cm2）. plasma nitriding increased the surface hardness from 300 HV50g for untreated sample, to around 800HV5og for nitrided samples at 1 mA/cm2. While the untreated samples exhibited a corrosion rate of 0.153 mm per year, the corrosion performance was improved up to 0.03 mm per year at current densities above 1 mA/cm2, which is about one fifth of the corrosion rate of the untreated sample.

关键词： plasma nitriding Current density Hardness Corrosion

Effects of plasma nitriding on Microstructure and Tribological Properties of CoCrMo Alloy Implant Materials

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Journal of Bionic Engineering 2010年第4期7卷 337-344页

作者： Qingliang Wang,Lei Zhang,Jiandong Dong School of Material Science and Engineering,China University of Mining & Technology,Xuzhou 221116,P.R.China [a] School of Material Science Engineering China University of Mining & Technology Xuzhou 221116 P. R. China

Medical forged CoCrMo alloy was treated by plasma nitriding *** microstructures were characterized by 3Dprofiler,SEM and *** tribological properties were investigated under lubrication of 25% bovine serum *** that plasma nitriding is a promising process to produce thick,hard,and more wear resistant layers on the surface of *** nitrided samples showed an important increase in the surface hardness due to the formation of harder CrN andCrN phases with compact nano-crystalline *** typical hardness values of HVincreased almost two times thanuntreated *** bovine serum lubrication,at low nitriding temperature the Coefficient of Friction (COF) of nitrided samplewas lower than that of untreated sample,but at high nitriding temperature the COF was almost the same as the untreated *** with the untreated sample,the nitrided samples showed lower wear rates and higher wear resistance under differentnitriding *** adhesive wear is the main mechanism for untreated CoCrMo alloy and the wear mechanisms ofnitrided ones are the fatigue wear and slight adhesive *** is concluded that the improvement of wear resistance is ascribed tothe hard nitride formation of CrN and CrN phases at the nitrided surfaces.

关键词： CoCrMo alloy plasma nitriding microstructure friction and wear

Improvement in Corrosion Resistance of Anchor Steel by Low Temperature plasma nitriding

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Journal of Wuhan University of Technology(Materials Science) 2014年第3期29卷 590-593页

作者：牛少卿杨双锁 LI Yi College of Mining Technology Taiyuan University of Technology State Key Laboratory of Coal Mine Disaster Dynamics and Control(Chongqing University)

plasma nitriding was used to improve the corrosion performance of anchor steel. The microstructure, phase constitution, microhardness and corrosion resistance of the nitrided layer were systematically studied. The results show that the nitrided layer is continuous and dense, and consists of Fe4N and Fe3N in the outmost surface. The microhardness of the nitrided sample is improved because of the formation of nitrides in the outer side continuous layer and the inner parts. The nitrided layer on the surface of anchor steel can effectively improve the corrosion resistance of the anchor steel.

关键词： plasma nitriding anchor steel corrosion resistance

IMPROVEMENT OF MECHANICAL PROPERTIES OF MARTENSITIC STAINLESS STEEL BY plasma nitriding AT LOW TEMPERATURE

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Acta Metallurgica Sinica(English Letters) 2008年第1期21卷 21-29页

作者： Y. T. Xi D.X. Liu D. Han Z.F. Han Corrosion and Protection Research Lab Northwestern Polytechnical University Xi＇an 710072 China Xi＇an Shaangu Power Co. Ltd Xi＇an 710611 China

A series of experiments were carried out to study the influence of low temperature plasma nitriding on the mechanical properties of AISI 420 martensitic stainless steel. plasma nitriding experiments were carried out for 15 h at 350℃ by means of DC- pulsed plasma in 25%N2＋ 75%H2 atmosphere. The microstructure, phase composition, and residual stresses profiles of the nitrided layers were determined by optical microscopy and X-ray diffraction. The microhardness profiles of the nitridied surfaces were also studied. The fatigue life, sliding wear, and erosion wear loss of the untreated specimens and plasma nitriding specimens were determined on the basis of a rotating bending fatigue tester, a ball-on-disc wear tester, and a solid particle erosion tester. The results show that the 350℃ nitrided surface is dominated by c-Fe3N and ON, which is supersaturated nitrogen solid solution. They have high hardness and chemical stabilities. So the low temperature plasma nitriding not only increases the surface hardness values but also improves the wear and erosion resistance. In addition, the fatigue limit of AISI 420 steel can also be improved by plasma nitriding at 350℃ because plasma nitriding produces residual compressive stress inside the modified layer.

关键词： Martensitic stainless steel plasma nitriding Low temperature Mechanical properties