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STUDy ON NODUlE RATIO AND COmPACTED GRAPHITE RATIO OF IRON FlUID TREATED By RARE EARTH mAGNESIUm AllOy QUICKly ExAmINED By CONCENTRATED DIFFERENCE FIxING OxyGEN

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Acta metallurgica Sinica(English letters) 1999年第5期12卷 907-910页

作者： l.x.ding and y.m.wang department of material, school of mechanical engineering, shenyang university, shenyang 110044, china

The article uses the method of regression statistics to obtain the regression formula of iron fluid nodule ratio Q and compacted graphite ratio R, through rare earth magnesium treatment. At the same time it has given thejudging figure of Q and R, considering oxygen activity and temperature. When using oxygen activity to judgenodule ratio and compacted graphite ratio of the ironfluid treated by rare earth magnesium alloy, its limit value changes with the change of temperature.

关键词： nodule ratio compacted graphite ratio oxygen activity oxygen concentration detector

FABRICATION AND PROPERTIES OF Al_2O_3 /Ni COmPOSITES

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Acta metallurgica Sinica(English letters) 1999年第5期12卷 903-906页

作者： l.x.ding 1) ,F.Zhang 2) ,Z.J.Zhao 3) ,y.m.wang 1) and x.D.Sun 2) 1) department of materials, school of mechanical engineering, shenyang university, shenyang 110044, china 2) school of materials and metallurgy, Northeastern Univers

Ceramic matrix composites consisting of an alumina matrix containing 20 vol% nickel particles has been fabricated using hot pressing technique. It is found that fracture toughness of the composite is much higher than the alumina matrix. This is due to the energy dissipation of the nickel particles that bridge the propagating cracks.

关键词： alumina nickel composites toughness

Solid solution strengthening of high-entropy alloys from first-principles study

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Journal of materials Science & Technology 2022年第26期121卷 105-116页

作者： H.l.Zhang D.D.Cai x.Sun H.Huang S.lu y.Z.wang Q.m.Hu l.Vitos x.D.ding State Key laboratory for mechanical Behavior of materials Frontier Institute of Science and TechnologyXi’an Jiaotong UniversityXi’an 710049China Key laboratory of Shaanxi Province for Craniofacial Precision medicine Research College of StomatologyXi’an Jiaotong UniversityXi’an 710049China department of materials Science and engineering The Ohio State University2041 College RoadColumbusOH 43210United States Institute of metal Research Chinese Academy of SciencesShenyang 110016China Science and Technology on Surface Physics and Chemistry laboratory Jiangyou 621908China Applied materials Physics Department of Materials Science and EngineeringRoyal Institute of TechnologyStockholm SE-10044Sweden

Solid solution strengthening(SSS)is one kind of strengthening mechanisms and plays an important role in alloy design,in particular for single-phase alloys including high-entropy alloys(HEAs).The classical labusch–Nabarro model and its expansions are most widely applicable to treating SSS of solid solution alloys including both conventional alloys(CAs)and *** this study,the SSS effects in a series of Febased CAs and HEAs are investigated by using the classical labusch–Nabarro model and its *** size misfit and shear modulus misfit parameters are derived from first-principles *** on available experimental data in combination with empirical SSS model,we propose fitting constants(i.e.,the ratio between experimental hardness and predicted SSS effect)for these two families of *** predicted host/alloy family-dependent fitting constants can be used to estimate the hardness of these SSS *** agreement between predicted and measured hardness values is satisfactory for both CAs and HEAs,implying that the proposed approach is reliable and successful.

关键词： Alloys Solid solution strengthening Hardness Size misfit parameter Shear modulus misfit parameter First-principles calculations

Simultaneous enhancement of mechanical and shape memory properties by heat-treatment homogenization of Ti_(2)Ni precipitates in TiNi shape memory alloy fabricated by selective laser melting

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Journal of materials Science & Technology 2022年第6期101卷 205-216页

作者： H.Z.lu l.H.liu C.yang x.luo C.H.Song Z.wang J.wang y.D.Su y.F.ding l.C.Zhang y.y.li National engineering Research Center of Near-net-shape Forming for metallic materials South China University of TechnologyGuangzhou 510640China musculoskeletal Oncology department Sun Yat-Sen University Cancer CenterGuangzhouGuangdong ProvinceChina shenyang Aircraft Design and Research Institute Shenyang 110035China Guangdong Huayi Plumbing Fittings Industry Co. Ltd.Kaiping 529321China school of engineering Edith Cowan University270 Joondalup DriveJoondalupPerthWA 6027Australia

The excellent shape memory and mechanical properties of Ti Ni shape memory alloys(SmAs) fabricated using selective laser melting(Slm) are highly desirable for a wide range of critical applications. In this study, we examined the simultaneous enhancement of mechanical and shape memory properties using heat-treatment homogenization of Ti_(2)Ni precipitates in a Ti_(50.6)Ni_(49.4)SmA fabricated using Slm. Specifically, because of the complete solution treatment, nanoscale spherical Ti_(2)Ni precipitates were homogeneously dispersed throughout the grain interior. Interestingly, the resultant SmA exhibited an ultrahigh tensile strength of 880 ± 13 mPa, a large elongation of 22.4 ± 0.4%, and an excellent shape memory effect, with a recovery rate of > 98% and ultrahigh recoverable strain of 5.32% after ten loading–unloading cycles. These simultaneously enhanced properties are considerably superior than those of most previously reported Ti Ni SmAs fabricated using additive manufacturing. Fundamentally, the enhancement in tensile strength is ascribed to precipitation strengthening and work hardening, and the large plasticity is mainly attributed to the homogeneous nanoscale globular Ti_(2)Ni precipitates, which effectively impeded the rapid propagation of microcracks. Furthermore, the enhanced shape memory properties are derived from the suppression of dislocation movement and formation of retained stabilized martensite by the presence of high-density dislocations, nanoscale Ti_(2)Ni precipitates, and abundant interfaces. The obtained results provide insight into the enhancement of the two types of properties in Ti Ni SmAs and will accelerate the wider application of SmAs.

关键词： Shape memory alloy Selective laser melting Heat treatment mechanical properties Shape memory properties

EFFECT OF PRECIPITANT ON THE PROPERTIES OF UlTRAFINE yTTRIA POWDER PRODUCED By PRE CIPITATION mETHOD

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Acta metallurgica Sinica(English letters) 1999年第5期12卷 1188-1193页

作者： y. Q. Jia1) , J. G. li1) , y. m. wang2) , l. x. ding2) , x. m . Qin1) and x. D. Sun1)1) school of materials and metallurgy , Northeastern university , shenyang 110006 , china2) department of materials , school of mechanical engineering , She

Using yttriu m nitrate as the m other salt , synthesis of ultrafine yttria po w der through w et che mical route w as investigated . Choice of precipitant has dra m atic effects on co m position ,particle size distribution and particle m orphology of the precipitates . When a m m onia solutionw as used as the precipitant , the precursor precipitate w as m ainly y2( O H) 5 14( N O3) 0 86· H2 O with co m paratively large particle size , broad size distribution and co m plex particleshapes . When sodiu m hydroxide solution w as used , roughly spherical α y( O H)3·3 H2 Opre cipitate w ith sm all particle size and narro w size distribution w as obtained . The transfor m a tion sequence of dry α y( O H)3 ·3 H2 O gel during calcination w as determ ined to be α y( O H) 3·3 H2 O→ y O O H→ y2 O3 . After calcining at 600 ℃ for 1 hour , both y2( O H) 5 14( N O3) 0 86· H2 O and α y( O H) 3·3 H2 O transfor m to well crystallized y2 O3 pow ders ,w ith particle sizes of 50 ～3000 n m and 20 n m , respectively .

关键词： KEyW ORDS yttria ultrafine pow der synthesis w et che mical route

Achieving high hetero-deformation induced(HDI)strengthening and hardening in brass by dual heterostructures

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Journal of materials Science & Technology 2022年第3期98卷 244-247页

作者： x.T.Fang Z.K.li y.F.wang m.Ruiz x.l.ma H.y.wang y.Zhu R.Schoell C.Zheng D.Kaoumi y.T.Zhu department of materials Science and engineering North Carolina State UniversityRaleighNC 27695USA Key laboratory for Anisotropy and Texture of materials of ministry of Education Northeastern UniversityShenyang 110819China school of Aeronautics and Astronautics Sichuan UniversityChengdu 610065China department of materials Science and engineering Texas A and M UniversityCollege StationTX 77840USA department of mechanical and Aerospace engineering North Carolina State UniversityRaleighNC 27695USA department of Nuclear engineering North Carolina State UniversityRaleighNC 27695USA Science and Technology on Thermostructural Composite materials laboratory Northwestern Polytechnical UniversityXi’an 710072China

Heterostructured materials,defined as materials that contain multiple zones with dramatically different flow stresses,have the potential to push the envelope of the strength-ductility of metals and alloys beyond what can be obtained conventionally[1–3].A prominent example is the heterogeneous lamella Ti that is as strong as its ultrafine-grained Ti,while as ductile as the coarsegrained Ti[4].

关键词： grain strengthening deformation

Effect of Temperature on material Transfer Behavior at Different Stages of Friction Stir Welded 7075-T6 Aluminum Alloy

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Journal of materials Science & Technology 2013年第10期29卷 955-960页

作者： S.D.Ji y.y.Jin y.m.yue S.S.Gao y.x.Huang l.wang Faculty of Aerospace engineering Shenyang Aerospace University State Key laboratory of Advanced Welding and Joining Harbin Institute of Technology

In this work, the morphologies of weld of 7075-T6 aluminum alloy via friction stir welding （FSW） were analyzed by optical microscopy, the temperature field was attained by numerical simulation, and the effect of temperature on material transfer behavior in the thermal-mechanical affected zone （TmAZ） at different stages was mainly investigated. The FSW process consists of three stages. It is very interesting to find that the maximum transfer displacement of material appears at the final stage of welding process, then at the stable stage and at the initial stage, which results from the difference of peak temperatures at different stages. At any stage, the material in TmAZ near the surface of weld transfers downwards, the material in the middle of weld moves upwards and the material near the bottom of weld hardly moves. In any cross section of weld, the largest transfer displacement of material appears in the middle of weld. The increase of rotational velocity and the decrease of welding speed are both beneficial to the transfer displacement of material in the middle of weld.

关键词： Friction stir welding 7075-T6 aluminum alloy Thermal-mechanical affected zone material transfer Numerical simulation

Enhanced helium ion irradiation tolerance in a Fe-Co-Ni-Cr-Al-Ti high-entropy alloy with l12 nanoparticles

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Journal of materials Science & Technology 2023年第12期143卷 169-177页

作者： y.l.Zhao F.l.meng T.yang J.H.luan S.F.liu G.m.yeli W.T.lin W.H.liu x.J.liu C.T.liu J.J.Kai school of materials Science and engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China school of materials Science and engineering Southern University of Science and TechnologyShenzhen 518055China department of materials Science and engineering Mechanical Behavior Division of Shenyang National Laboratory for Materials ScienceCity University of Hong KongHong KongChina department of mechanical engineering City University of Hong KongHong KongChina Institute of Nuclear&New Energy Technology Tsinghua UniversityBeijing 100084China

l12-strengthened high entropy alloys(HEAs)with excellent room and high-temperature mechanical prop-erties have been proposed as promising candidates as structural materials for advanced nuclear ***,knowledge about their radiation response is fairly *** the present work,a novel HEA with a high density of l12 nanoparticles was irradiated with He ion at 500°*** electron microscope(TEm)and atom probe tomography(APT)were employed to study the evolution of mi-crostructural stability and radiation-induced *** to the single-phase FeCoNiCr HEA,the main microstructural features were numerous large faulted dislocation loops and helium *** the irradiation resistance of the present l12-strengthened HEA is much improved in terms of reduced bubble size,which could be attributed to the considerable He trapping efficiency of the coherent pre-cipitate/matrix interface and the enhanced capability of the interface for damage elimination when the matrix channel width is *** analysis revealed that an inverse-Kirkendall-mechanism-dominated radiation-induced segregation(RIS)occurs around bubbles,where a significant Co enrichment and Ni de-pletion can be clearly *** addition,the competing dynamics of ballistic mixing and elemental clustering that raised from the irradiation-enhanced diffusion in a highly supersaturated matrix,along with the low precipitation nucleation barrier due to the small lattice misfit,lead to a dynamical pre-cipitation dissolution and re-precipitation appears under *** a promising phenomenon is expected to promote a potential self-healing effect and could in turn provide a sustainable irradiation tolerance over the operational lifetime of a reactor.

关键词： l12 nanoparticles High-entropy alloy Helium bubble Phase stability Radiation-induced segregation

高镍316l不锈钢连铸方坯凝固模式及残留铁素体特征

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钢铁 2024年第5期59卷 80-91页

作者：王洋陈蕾牟望重张政睿王剑陈超太原理工大学材料科学与工程学院山西太原030024 太原理工大学机械与运载工程学院山西太原030024 瑞典皇家工学院材料科学与工程系瑞典斯德哥尔摩SE10044 东北大学材料电磁过程研究教育部重点实验室辽宁沈阳110819

奥氏体不锈钢中的残留铁素体对其使用性能有着重要影响,而残留铁素体特征主要与成分、冷却速率和凝固模式有关。研究了高镍含量316l奥氏体不锈钢连铸方坯,其成分位于共晶点附近,凝固模式容易发生改变。采用金相显微镜(Om)、image-pro-p... 详细信息

奥氏体不锈钢中的残留铁素体对其使用性能有着重要影响,而残留铁素体特征主要与成分、冷却速率和凝固模式有关。研究了高镍含量316l奥氏体不锈钢连铸方坯,其成分位于共晶点附近,凝固模式容易发生改变。采用金相显微镜(Om)、image-pro-plus软件计算等方法,探究316l奥氏体不锈钢连铸方坯沿厚度方向残留铁素体特征及分布规律。结果表明,残留铁素体沿厚度方向呈现短棒状、颗粒状、骨骼状和网状结构,其铁素体分布情况与板坯中“m”形分布相似。铸坯表面到距铸坯表面55 mm处,铁素体体积分数在2%左右波动,在距铸坯65 mm处,铁素体体积分数增加到最高值(4.77%),随后75 mm处铁素体体积分数又突然降低,从75 mm到中心铁素体体积分数有增加趋势。使用电子探针(EPmA)分析发现,Cr、Ni、mo、Si、mn等元素都出现了不同程度的微观偏析现象,同时发现由铁素体通过固态相变形成的二次奥氏体还保留部分铁素体的成分特征。使用热力学计算软件(Thermo-Calc)计算了Fe-Cr-Ni三元相图以及铸坯边部和中心的平衡凝固过程,计算结果表明,铸坯边部以FA模式凝固,铸坯中心以AF模式凝固。通过残留铁素体形貌判断的凝固模式与热力学计算结果不同,铸坯在边部和中心以AF模式凝固,在柱状晶区出现了以FA模式凝固的骨骼状铁素体。最后分析了残留铁素体分布的形成机理,表面细晶区铁素体体积分数较少,这是由于表面凝固模式为AF模式;在距铸坯表面65 mm处铁素体体积分数增加到最高值,这是由于凝固模式发生了由AF模式向AF+FA模式的转变;75 mm处铁素体体积分数降低,这是由于凝固模式又转变为了AF模式;从75 mm处到铸坯中心,等轴晶结构和冷却速率降低使得固态相变所需的扩散距离增加,导致铁素体体积分数增加。

关键词： 316l奥氏体不锈钢铁素体形貌铁素体体积分数热力学计算凝固模式

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