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Wear behavior of Ti6Al4V biomedical alloys processed by selective laser melting, hot pressing and conventional casting

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Transactions of Nonferrous metals Society of China 2017年第4期27卷 829-838页

作者： F.BARTOLOmEU m.BUCIUmEANU E.PINTO N.ALVES F.S.SILVA O.CARVALHO G.mIRANDA Center for micro-Electro mechanical Systems (CmEmS-Uminho) University of Minho Azurem 4800-058 Guimaraes Portugal Cross-Border Faculty of Humanities Economics and Engineering"Dunarea de Jos" University of Galati Domneasca 47 800008 Galati Romania Centre for Rapid and Sustainable Product Development Polytechnic Institute of Leiria Rua General Norton de Matos Apartado 4133 2411-901 Leiria Portugal

The aim of this work was to study the influence of the processing route on the microstructural constituents,hardness andtribological(wear and friction)behavior of Ti6Al4V biomedical *** this sense,three different processing routes were studied:conventional casting,hot pressing and selective laser melting.A comprehensive metallurgical,mechanical and tribologicalcharacterization was performed by X-ray diffraction analysis,vickers hardness tests and reciprocating ball-on-plate wear tests ofTi6Al4V/Al2O3sliding *** results showed a great influence of the processing route on the microstructural constituents andconsequent differences on hardness and wear *** highest hardness and wear resistance were obtained for Ti6Al4Valloy produced by selective laser melting,due to a markedly different cooling rate that leads to significantly different microstructurewhen compared to hot pressing and *** study assesses and confirms that selective laser melting is potential to producecustomized Ti6Al4V implants with improved wear performance.

关键词： biomedical alloy Ti6Al4V alloy wear behavior microstructure selective laser melting hot pressing casting

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Effect of Laser Cladding Processing Parameters on Nitinol’s Clad Dimensions, microstructure, and Hardness

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materials Sciences and Applications 2021年第12期12卷 603-613页

作者： Engy m. Zain Ahmed Farid Youssef Ahmad El Sabbagh Sisa Pityana mohamed A. Taha Design and Production Engineering Department Faculty of Engineering Ain Shams University Cairo Egypt National Laser Centre The Council for Scientific and Industrial Research Pretoria South Africa

Nickel Titanium alloy (Nitinol) is characterized by its good mechanical properties, good damping properties in addition to its distinctive shape-memory effect and superelasticity effect besides its great bio-mechanical compatibility and corrosion resistance. These properties have empowered its applications, particularly within the bio-medical and aerospace industry. Despite these exceptional properties, the manufacturing of Nitinol by conventional methods is exceptionally troublesome and costly and consequently must be inspected. Therefore, additive manufacturing specifically laser-based ones were used recently. In this research, the effect of processing parameters of laser cladding/laser direct deposition on Nitinol’s microstructure, Hardness and Clad Dimensions was evaluated. Systematic characterization of Nitinol samples was done utilizing Optical microscopy and vickers hardness tester. Samples of Nitinol were synthesized with different processing parameters using laser cladding and its properties were investigated and compared to one another to get the optimum processing parameters to synthesize a near net shape, fully dense Nitinol component with reliable properties. The results showed that there’s a processing parameter window at which the alloy possesses its best mechanical and functional properties which were of Laser power of value 1.25 Kw, Scan speed of 1.5 m/min and powder deposition rate of 1.5/1.5 RPm, these conditions resulted in the formation of martensite phase which is responsible for its functional properties with 40% volume fraction and a hardness value of 598 HV.

关键词： Nitinol Shape memory Alloy Additive manufacturing Hardness microstructure

microstructural and mechanical Characterization after Thermomechanical Treatments in 6063 Aluminum Alloy

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materials Sciences and Applications 2011年第11期2卷 1529-1541页

作者： Waldemar A. monteiro Iara m. Espósito Ricardo B. Ferrari Sidnei J. Buso 不详

The aim of this work is the mechanical and microstructural characterization by optical and electron microscopy as well as microhardness of Al 6063 alloy after mechanical and thermal treatment. Al-mg based alloys have special attention due to the lightness of the material and certain mechanical properties and recyclability. Such alloys produce good mechanical properties in moderate mechanical efforts (up to 700 mPa) and good resistance to the corrosion. Cold rolling steps (30%, 60% and 90% in area reduction) in Al 6063 alloy were employed for the recrystallization studies, followed by thermal treatment using four isothermal heating (423K, 523K, 623K and 723K) during 1800, 3600, 5400 and 7200s. The direct observation and chemical microanalysis were made in a JEOL200C and JEOL2010 transmission electron microscopes combined with mechanical characterization utilizing vickers microhardness measurements. Normally classified as non-heat-treatable these alloys obtain higher strength either by strain-hardening or by solid solution. The nucleation of new grains is a non stability of the deformed microstructure, depending on subgrain size heterogeneities present as potential embryos in the deformed state adjacent to high local misorientation. The results indicate a significant effect of second-phase particles on recrystallization and how to control the resulting microstructure and texture by the use of particles. It may be a preferential growth in the early stage due to their local environment or a selection of certain orientations from among those produced by particles stimulated nucleation or a preferential nucleation at particles in favored sites such as grain boundaries.

关键词： 6063 Aluminum Alloy Optical microscopy Electron microscopy Hardness

PROCESSING, mICROSTRUCTURE AND mECHANICAL PROPERTIES OF mo SILICIDES AND THEIR COmPOSITES

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中国有色金属学会会刊：英文版 1999年第S1期9卷 1-12页

作者： P.D.Eason, E.N.Ross, L.A.Dempere, and m.J.Kaufman Department of materials Science and Engineering, University of Florida, Gainesville, FL 32611 U.S.A.

Phase relations in the mo Si C, mo Si Al and mo Si Ti B systems were investigated via sample production, heat treatment and characterization, using light optical microscopy(LOm), scanning electron microscopy(SEm), electron probe microanalysis(EPmA), X ray diffraction(XRD), image analysis, light element analysis, vickers hardness and fracture toughness measurements. The results led to many signigicant conclusions.

关键词： mo silicides processing microstructure mechanical properties

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microstructure, Adhesion and Wear of Plasma Sprayed AlSi-SiC Composite Coatings

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Journal of Surface Engineered materials and Advanced Technology 2012年第3期2卷 227-232页

作者： Satish Tailor V. K. Sharma R. m. mohanty P. R. Soni Council of Scientific and Industrial Research CSIR-HQS New Delhi India. Department of metallurgical and materials Engineering Malaviya National Institute of Technology Jaipur India

Al-12.5 wt% Si alloy powder with 15 wt% SiCp was mechanically alloyed (mA) using attrition mill in purified nitrogen atmosphere. The mA processed powder was found to have nano grain size and uniform distribution of SiCp in the AlSi matrix. This mA processed powder was used for atmospheric plasma spraying (APS) for varying distances and currents densities. The coatings obtained were studied by image analyzer, SEm and XRD. microhardness and wear rate of the coatings were evaluated using vickers indenter and pin on disk type tribometer, respectively. Adhesion strength of the coatings was measured by interfacial indentation test. The results showed that these coatings have uniform distribution of reinforced SiC particles in the nano crystalline matrix, low porosity (1% - 2%), low wear rates and improved adhe-sion strength. It was also observed that by increasing current density of APS, the adhesive strength increased.

关键词： AlSi-SiC Attrition milling Plasma Spray Coating Adhesion Strength Wear Resistance

Langenskiold Procedure for madelung’s Deformity:Case Series of Late Sequelae

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Open Journal of Orthopedics 2014年第11期4卷 313-320页

作者： Emma C.Paes Caroline m.J.Theunissen Ralph J.B.Sakkers Arnold H.Schuurman Departments of Plastic Reconstructive and Hand SurgeryUniversity Medical Centre UtrechtUtrechtThe Netherlands Department of Orthopaedic Surgery University Medical Centre UtrechtUtrechtThe Netherlands

Background: Although many authors advise to postpone surgical intervention until skeletal maturity is reached, the Langenskiöld procedure—entailing physiolysis and the release of vickers’ ligament—is a known procedure in case of madelung’s deformity in children. Although advised in textbooks and recent reviews, the results and late sequelae of this procedure have been poorly documented. The aim of this study is to portray the late effects of this procedure for three patients and emphasize a very careful patient selection. methods: A retrospective study was performed of the medical records of three patients who underwent a Langenskiöld procedure with release of vickers’ ligament for madelung’s deformity of the wrist. They were recalled for function evaluation and their results are presented in the current study. Results: We report the long term results of three patients (five wrists) who underwent a Langenskiöld procedure with release of vickers’ ligament in detail. mean follow-up was twelve years (range: 11 - 14 years). In all of the operated wrists severe pain recurred due to destruction of the distal radio-ulnar joint. Further salvaging surgeries were necessary, some with highly dissatisfying results. Conclusions: Based on our experience we advise not to perform this procedure until further studies have proven its effectiveness and clear indications. Other techniques are available for later correction of madelung’s deformity, with similar results on pain relief, wrist function and cosmetics. However, we will advocate conservative treatment until skeletal maturity is reached.

关键词： madelung’s Deformity Treatment Langenskiold Physiolysis vickers’Ligament

mSATSI:结合可靠经典方法的新简化用户处理及可视化工具的应力反演mATLAB软件包

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世界地震译丛 2014年第4期45卷 34-45页

作者： P.martínez-Garzón G.Kwiatek m.Ickrath m.Bohnhoff 崔华伟防灾科技学院

根据地震震源机制估计应力场方向是理解地壳力学以及地震物理现象的一个相关方法。在全球地震学中，法向应力反演（FSI）是研究与大地震发生相关的构造过程的一个较为成熟的技术（如Hardebeckandmi—chael，2004；Yoshidaetal，2012）。

关键词： mATLAB软件包应力场可视化工具经典方法反演用户地震学物理现象

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碳化物形态对40Crmo钢切削性的影响

华侨大学学报(自然科学版) 1986年第3期7卷 291-299页

作者：陈子文 E.m.Trent m.L.H.Wise 华侨大学英国伯明翰大学

在用高速钢刀具切削中,通常认为被加工材料的硬度直接影响其切削性.用极限切削速度作为评定切削性的标准(刀具切削时间为30秒),发现工件的硬度值固然重要,然而其金相显微组织却强烈地影响钢的切削性.40Crmo钢通过不同热处理后,具有相同... 详细信息

在用高速钢刀具切削中,通常认为被加工材料的硬度直接影响其切削性.用极限切削速度作为评定切削性的标准(刀具切削时间为30秒),发现工件的硬度值固然重要,然而其金相显微组织却强烈地影响钢的切削性.40Crmo钢通过不同热处理后,具有相同硬度值下获得不同的金相显微组织.完全球化的碳化物形态具有最佳的切削性,最大切削速度为90米/分,不完全球化碳化物相的切削速度为76米/分,具有片状碳化物形态的供应(轧制)状态为69米/分. 试验得出:一定硬度值下,钢的切削性取决于钢中珠光体或回火马氏体的碳化物形态和切削过程中碳的溶解度.

关键词：切削速度切削用量切削性切屑厚度积屑瘤球化退火滞流层碳化物尺寸刀具金相显微组织珠光体金相相组成

Electrochemical Corrosion Study in H₂SO₄ of NiAl with Cu Additions, microstructure and micro-Hardness at Room Temperature

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Journal of minerals and materials Characterization and Engineering 2022年第3期10卷 225-241页

作者： Jesús m. Colín de la Cruz Sergio A. Serna Barquera Alvaro Torres-Islas Arturo molina-Ocampo Edgar Valenzuela José G. González Rodríguez Universidad Autónoma del Estado de morelos Facultad de Ciencias Químicas e Ingeniería UAEM-FCQeI. Av. Universidad 1001Colonia Chamilpa Cuernavaca Morelos México Universidad Autónoma del Estado de morelos Centro de Investigación en Ingeniería y Ciencias Aplicadas UAEM-CIICAp Cuernavaca Morelos México UABC Baja California Sur México

For many years, intermetallic materials promise applications in a wide variety of technology areas. NiAl intermetallic compound is material that exhibits important characteristics such as high corrosion resistance and low density besides its ability to retain strength and stiffness at elevated temperatures. However NiAl intermetallic is too hard, brittle and exhibits very low ductility at room temperature being the reason because this material is not yet available for structural applications. In order to increase the ductility of the NiAl intermetallic compound, the addition of a third alloying element has been proved, nevertheless it is important to determine if such additions decrease or increase the hardness and the corrosion resistance of the alloy. So, the present investigation reports the corrosion performance of the NiAl intermetallic compound modified with Cu, emphasizing the EIS analysis and the relation between physical parameters and the modelling equations used in the Equivalent Electric Circuit. It was found that the addition of Cu promotes the formation of the γ’-Ni3Al phase in Cu contents greater than 15 at. %, in addition to a decrease in micro hardness and an increment in the Icorr values. In this way, the electrochemical characterization evidenced a high corrosion resistance of these intermetallic alloys.

关键词： NiAl-Cu Corrosion Behavior Electrochemical Impedance Spectrum vickers micro Hardness microstructure