检索结果-南通市图书馆

Journal of Rare Earths 2010年第4期28卷 627-630页

作者：韦小园黄晖陈子勇王为李聪颖聂祚仁 College of Materials Science and Engineering Beijing University of Technology

The Al-Mg-Mn-Zr-Er alloy sheets with a thickness of 4 mm were welded by TIG welding, the microstructures and mechanical properties of Al-Mg-Mn-Zr-Er alloy weld joints filled with Φ1.6 mm Al-Mg-Mn-Zr and Al-Mg-Mn-Zr-Er welding wires were studied by optical microscopy, scanning electron microscopy, transmission electron microscopy, hardness testing and tensile mechanical properties testing. The result showed that, the tensile strength increased by 57 MPa and the coefficient of weld joint reached 0.8 when Al-Mg-Mn-Zr-Er welding wire was used as filling material. The tensile strength and elongation of weld joint filled with Al-Mg-Mn-Zr-Er welding wire were 19% and 85% higher those that of filled with Al-Mg-Mn-Zr welding wire respectively, which resulted from grain refinement strengthening and dispersion strengthening of Al3Er.

关键词： Al-Mg-Mn-Zr-Er welding wire weld joint microstructure and mechanical properties dispersion strengthening rare earths

Effect of extrusion on the microstructure and mechanical properties of a low-alloyed Mg-2Zn-0.8Sr-0.2Ca matrix composite reinforced by TiC nano-particles

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2022年第11期29卷 1981-1990页

作者： Zedong Wang Kaibo Nie Kunkun Deng Jungang Han College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi Key Laboratory of Advanced Magnesium-based Materials Taiyuan University of TechnologyTaiyuan 030024China

A low-alloyed Mg-2Zn-0.8Sr-0.2Ca matrix composite reinforced by TiC nano-particles was successfully prepared by semi-solid stirring under the assistance of ultrasonic,and then the as-cast composite was hot *** results indicated that the volume fraction of dynamical recrystallization and the recrystallized grain size have a certain decline at lower extrusion temperature or *** finest grain size of~0.30μm is obtained in the sample extruded at 200℃ and 0.1 mm/*** as-extruded sample displays a strong basal texture intensity,and the basal texture intensity increases to 5.937 mud while the extrusion temperature increases from 200 to 240℃.The ultra-high mechanical properties(ultimate tensile strength of 480.2 MPa,yield strength of 462 MPa)are obtained after extrusion at 200℃ with a rate of 0.1 mm/*** all strengthening mechanisms for the present composite,the grain refinement contributes the most to the increase in strength.A mixture of cleavage facets and dimples were observed in the fracture surfaces of three as-extruded nanocomposites,which explain a mix of brittle-ductile fracture way of the samples.

关键词： magnesium matrix composite extrusion microstructure and mechanical properties texture fracture

Effect of austempering parameters on microstructure and mechanical properties of horizontal continuous casting ductile iron dense bars

在线全文

学校读者我要写书评

暂无评论

China Foundry 2015年第2期12卷 104-110页

作者： Chun-jie Xu Pan Dai Zheng-yang Zhang Zhong-ming Zhang Jin-cheng Wang Yong-hui Liu School of Materials Science and Engineering Xi'an University of Technology State Key Laboratory of Solidification Processing Northwestern Polytechnical University Shaanxi Hua An Continuous Casting Co. Ltd.

In the present research, the orthogonal experiment was carried out to investigate the influence of different austempering process parameters （i.e. austenitizing temperature and time, and austempering temperature and time） on microstructure and mechanical properties of LZQT500-7 ductile iron dense bars with 172 mm in diameter which were produced by horizontal continuous casting （HCC）. The results show that the major factors influencing the hardness of austempered ductile iron （ADI） are austenitizing temperature and austempering temperature. The fraction of retained austenite increases as the austenitizing and austempering temperatures increase. When austenitizing temperature is low, acicular ferrite and retained austenite can be efifciently obtained by appropriately extending the austenitizing time. The proper austmepering time could ensure enough stability of retained austenite and prevent high carbon austenite decomposition. The optimal mechanical properties of ADI can be achieved with the fol owing process parameters： austenitizing temperature and time are 866 ＆#176;C and 135 min, and austempering temperature and time are 279 ＆#176;C and 135 min, respectively. The microstructure of ADI under the optimal austempering process consists of ifne acicular ferrite and a smal amount of retained austenite, and the hardness, tensile strength, yield strength, elongation and impact toughness of the bars are HBW 476, 1670 MPa, 1428 MPa, 2.93%and 25.7 J, respectively.

关键词： horizontal continuous casting (HCC) ductile iron dense bars austempered ductile iron (ADI) microstructure and mechanical properties orthogonal test

Effects of Quenching Process on microstructure and mechanical properties of Low Carbon Nb-Ti Microalloyed Steel

在线全文

学校读者我要写书评

暂无评论

Journal of Harbin Institute of Technology(New Series) 2013年第4期20卷 73-77页

作者： Wen-Zhen Xia Xian-Ming Zhao Xiao-Ming Zhang Di Wu State Key Laboratory of Rolling and Automation Northeastern University

The low carbon Nb-Ti mieroalloyed tested steel was prepared by the process of vacuum induction furnace smelting, forging and hot rolling. The new steel aims to meet the demand of high strength, high toughness and high plasticity for building facilities. The effects of quenching process on microstructure and mechanical properties of tested steel were investigated. The results showed that prior austenite grain size, phase type and precipitation behavior of （ Nb, Ti）（ C, N） play important roles in mechanical properties of the steel. Through modified appropriately, the model of austenite grain growth during heating and holding is d^5.7778 = 5. 6478^5.7778 ＋ 7.04 × 10^22t^1.6136 exp（- 427. 15 ×10^3 /（RT））. The grain growth activation energy is Qg = 427. 15 kJ. During quenching, the microscopic structures are mainly martensite and lath bainite which contains lots of lath substructure and dislocations. The content of phases, fine and coarsening （ Nb, Ti ）（ C, N ） precipitated changes during different quenching temperatures and holding time. Finally compared with the hardness value, the best quenching process can be obtained that heating temperature and holding time are 900 ℃ and 50 mins, respectively.

关键词： low carbon Nb-Ti mieroalloyed steel quenching process austenite grain growth model microstructure and mechanical properties

Pseudo-spinodal mechanism approach to designing a near-βhigh-strength titanium alloy through high-throughput technique

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2021年第8期40卷 2099-2108页

作者： Li-Gang Zhang Jing-Lu Tang Zhen-Yu Wang Jing-Ya Zhou Di Wu Li-Bin Liu Patrick J.Masset School of Material Science and Engineering Central South UniversityChangsha410083China Key Laboratory of Nonferrous Metallic Materials Science and Engineering Ministry of EducationChangsha410083China State Key Laboratory of Powder Metallurgy Changsha410083China Faculty of mechanical Engineering Koszalin University of TechnologyKoszalin75-453Poland

The main reason for the high strength in near-βtitanium alloys is the ultrafine precipitation of the acicular secondary a phase in theβ*** purpose of this study is to use the pseudo-spinodal mechanism to obtain the ultrafine a phase for the design of a new high-strength near-γtitanium *** calculations and TC21-(TC21+15 Mo)diffusion couple composition gradient experiments were used to demonstrate that TC21+3 Mo alloy can undergo a pseudo-spinodal decomposition to obtain the ultrafine a phase,resulting in a high-strength *** adjusting the heat treatment process to obtain a bimodal microstructure,the alloy exhibits a good balance between ultimate tensile strength(1351 MPa)and plasticity(8.5%strain).Thus,it was demonstrated that the pseudospinodal mechanism combined with a high-throughput diffusion couple technique is an effective method for designing high-strength titanium alloys.

关键词： High-strength titanium alloy TC21+xMo Diffusion couple Pseudo-spinodal mechanism microstructure and mechanical properties

Study of Mg-Al-Ca magnesium alloy ameliorated with designed Al8Mr4Gd phase

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2020年第4期8卷 1084-1089页

作者： Chaosheng Ma Wenbo Yu Xufeng Pi Antoine Guitton School of mechanical and Electronic Control Engineering Beijing JiaoTong UniversityBeijingChina Universite de Lorraine-CNRS-Arts et Metiers ParisTech-LEM3 F-57000 MetzFrance Laboratory of Excellence on Design of Alloy Metals for low-niAss Structures(DAMAS) Universite de LorraineF-57073 MetzFrance

To investigate the effect of AlsMn4Gd phase on microstructural and mechanical properties of Mg-Al-Ca magnesium alloy,two Mg-2.5AbCa and Mg-2.5Al2Ca-0.1 Al8Mn4Gd alloys were designed and compared in this *** results show that a small amount of Gd can significantly refine a-Mg grains and change the morphology of AUCa ***,the formed Al8Mn4Gd phase could serve as a heterogeneous nucleation site for the a-Mg grains and AbCa ***,the introduction of Gd not only optimized the mechanical properties of Mg-Al-Ca alloy,but also facilitated the thermal deformation(such as hot rolling).

关键词： Mg-Al-Ca alloy AlgNlruGd phase microstructure and mechanical properties Hot rolling.

A Special TMCP Used to Develop a 800MPa Grade HSLA Steel

在线全文

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2001年第3期8卷 224-228页

作者： Chengjia Shang,Xuemin Wang, Xinlai He, Shanwu Yang, Yi Yuan Material Science and Engineering School, University of Science and Technology Beijing, Beijing, 100083, China Material Science and Eng. School Univ. of Sci. and Technol. Beijing Beijing 100083 China

The effect of relaxation after finished rolling on structures and properties of four microalloyed steel with different content of Nb and Ti was investigated. By alloy designing and control rolling + relaxation-precipitation-control phase trail storm ati on (RPC) process, a new 800 MPa grade HSLA plate steel could be obtained, the microstructure is composite ultra-fine lath bainite/martensite. The tempering process and mechanical properties of this kind of HSLA steel were investigated. The yield strength can achieve 800 MPa, and the ductility and impact toughness is satisfied.

关键词： HSLA steel microstructure and mechanical properties TMCP (thermomechanical control process) RPC

Combustion Synthesis and Densification of NiAl/TiB_2 Composites

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2002年第1期17卷 4-9页

作者：王为民 WuhanUniversityofTechnology

A suitable combustion synthesis and densification process was designed to fabricate dense NiAl/ TiB2 composites from Ni-Al- Ti-B system. Combustion synthesis processing and microstructure characteristics of products were studied in detail. The results show that the amount of TiB2 ceramics has a great influence on the combustion synthesis processing and microstructure; with the increase of the amount of TiB2 ceramics, the combustion temperature and combustion velocity increase rapidly. The volume of synthesized products and the grain size of ceramics particle size are also affected by the amount of TiB2 ceramics. TiB2 ceramics fiber can be produced in this synthesis system. The dense NiAl/ TiB2 composites with residual porosity of no more than 1% are fabricated by the combustion synthesis and hot pressing, the mechanical properties of the dense NiAl/ TiB2 composites increase with increase of the amount of TiB2 ceramics.

关键词： NiAl/ TiB2 composites combustion synthesis and hat pressing microstructure and mechanical properties