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Search Results: 1 - 10 of 5547 matches for " China Korea Institute of Machinery and Materials "
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Microstructural Evolution and Thermal Stability of Ultra-fine Grained Al-4Mg Alloy by Equal Channel Angular Pressing
Hongbin GENG,Subbong KANG,Shiyu HE,
Hongbin GENG
,Subbong KANG,Shiyu HE School of Materials Science and Engineering,Harbin Institute of Technology Harbin,China Korea Institute of Machinery and Materials,Sangnam Dong,Changwon,Kyungnam -,South Korea

材料科学技术学报 , 2004,
Abstract: Experiments were conducted to evaluate the grain refinement and thermal stability of ultra-fine grained Al-4Mg alloy introduced by equal-channel angular pressing (ECAP) at 473 K. The results show that the intensities of X-ray (111/222) and (200/400) peaks for the alloy processed by ECAP decrease significantly and the peak widths of half height become broadening compared with the corresponding value in the annealed alloy. The microstructure of 2 passes ECAPed alloy consists of both elongated and equiaxed subgrains. The residual strain in the alloy increases with increasing passes numbers, that appears as increasing dislocation density and lattice constant of matrix. An equiaxed ultra-fine grained structure of ~0.2μm is obtained in the present alloy after 8 passes. The ultra-fine grains are stable below 523 K, because the alloy retains extremely fine grain size of ~1μm after static annealing at 523 K for1 h.
RECRYSTALLIZATION-INDUCED PLASTICITY IN 18Ni MARAGING STEEL UNDER ELASTIC STRESS
YIN Zhongda Harbin Institute of Technology,Harbin,China ZHOU Yongkang Shanghai Centrifugal Machinery Research Institute,Shanghai,China YIN Zhongda Faculty of Heat Treatment of Materials,Harbin Institute of Technology,Harbin,China,
YIN Zhongda Harbin Institute of Technology
,Harbin,China ZHOU Yongkang Shanghai Centrifugal Machinery Research Institute,Shanghai,China YIN Zhongda Faculty of Heat Treatment of Materials,Harbin Institute of Technology,Harbin,China

金属学报(英文版) , 1990,
Abstract: An approach to study the recrystallization-induced plasticity(RIP)phenomenon in the 18Ni maraging steel under the elastic stress has been made by the analysis of dynamic behaviour at elevated temperatures,the phenomenological analysis of dynamic strain feature curves,the confirmation of phase transformation point and TEM observation of RIP processing itself.
A Study on Alnico Permanent Magnet Powders Prepared by Atomization
Changbin SONG,Bocksoo HAN,Ying LI,
Changbin SONG
,Bocksoo HAN,Ying LI Division of Materials Engineering,Kongju National University,Kongju,Korea Division of mechanical Engineering,Hanbat National University,Taejon,Korea Institute of Materials,Shanghai University,Shanghai,China

材料科学技术学报 , 2004,
Abstract: Alnico powders were prepared by gas atomization process. Composition of the Alnico powders was Fe37.1 Al8.2 Ni17.6-Co26.6 Cu3.3 Ti7.2 (wt pct) which was the same as that of commercially available Alnico magnets. Average particle size of the powders was 119μm. Effects of heat treatment in magnetic field on magnetic properties of the powders were investigated. The optimum process of heat treatment was found as follows, heated at 870℃ for 1 min first, then cooled down to 700℃ at cooling rate 0.3℃/s in magnetic field, and finally aged isothermally for 4 h.Magnetic properties of the Alnico powders were measured and the results were that intrinsic coercivity iHc was 1.0kOe and remanence Mr was 36.5 emu/g.
FORM AND EFFECT OF Zr IN CuCoBeZr ALLOY
LIU Hefa SUN Naizhen DAI Xueli REN He Zhenjiang Shipbuilding Institute,Zhenjiang,Jiangsu,ChinaLI Lijun Shanghai,Electrical Machinery Plant,
LIU Hefa SUN Naizhen DAI Xueli REN He Zhenjiang Shipbuilding Institute
,Zhenjiang,Jiangsu,China LI Lijun Shanghai,Electrical Machinery Plant.Shanghai.China professor.Institute of Metallic Materials Research,Zhenjiang Shipbuilding Institute,Zhenjiang,Jiangsu,China

金属学报(英文版) , 1993,
Abstract: Precipitation form of Zr in CuCoBeZr alloy during solidificotion.cooling and final aging,as well as its effect on the high temperature properties have been studied and discussed.Results show that during solidificotion and cooding.Zr precipitates as fine particle.Cu_3Zr,which pre- vents X-Cu grains from growing and provides more nuclei for CoBe and hence leads to finer primary CoBe.Fine Cu_3Zr partrticles also precipitate during aging. Because Co_3Zr is difficult to coalesce at high temperatures,the recrystallization temper- uture increases and the high temperature mechanical properties improve.
Effect of Temperature and Ram Speed on Isothermal Extrusion for Large-size Tube with Piece-wing
He YANG,Jun ZHANG,Yangmin HE,Bingtao HAN,
He YANG
,Jun ZHANG,Yangmin HE and Bingtao HAN College of Materials Science and Engineering,Northwestern Polytechnical University,Xi''''an,China Xi''''an Heavy Machinery Research Institute,Xi''''an,China

材料科学技术学报 , 2005,
Abstract: Heat energy change during the extrusion of 7075 aluminium alloy large-size tube with piece-wing in a container was analyzed. Extrusion load vs ram displacement diagrams and exit temperature vs ram displacement diagrams at various speeds were obtained by 3D FEM simulation. Results show that the exit temperature becomes higher as the ram speed and displacement increase. For large-size tube with piece-wing, there is certainly a curve of ram speed decreasing with increasing ram displacement, which enables isothermal extrusion to be achieved. Therefore,an attempt was made to divide the working stroke into five different zones. Each of them has a preset speed that decreases from the ram displacement beginning to the ending. And then, new exit temperature vs ram displacement diagram was obtained by 3D FEM simulation for the five different speeds. It is shown that the variation of exit temperature is very small. Through the above research, a basic method for realizing isothermal extrusion of 7075large-size tube with piece-wing was obtained, that is, the working stroke was divided into several different zones with a decreasing speed during extrusion, each zones' speed was real-time adjusted on the feedback signal of exit temperature by proportional hydraulic valve through closed-loop control. The engineering experiment verification was carried out on 100 MN aluminium extrusion press with oil-driven double action. The experimental results of the exit temperature agrees with the simulation ones. The achievements of this study may serve as a significant guide to the practice of the relevant processes, particularly for isothermal extrusion. The verified method has been used in the design and manufacture of 125 MN aluminium extrusion press with oil-driven double action.
THE REINFORCING MECHANISM OF TiB2 IN TiB2/A357 COMPOSITE
THE REINFORCING MECHANISM OF TiB2 IN TiB2/A357 COMPOSITE

BYu,YJZhang,ZXZhao,FXZhao,QKCai,CSLiu,
B. Yu Y.J. Zhang Z.X. Zhao F.X. Zhao Q.K. Cai and C.S.Liu Shenyang Research Institute of Foundry
,The Chinese Academy of Machinery Sciences,Shenyang,China School of Materials & Metallurgy,Northeastern University,Shenyang,China East China University of Science and Technology,Shanghai,China

金属学报(英文版) , 2003,
Abstract: Mechanical properties were tested for in situ TiB2/A357 composite fabricated by LSM (mixed salts reaction) method. Microstructures of as cast and plastic deformed TiB2/A357 were investigated. The results show that there is a low misfit between (200)A1 and (101)TiB2 with 011]Al // 101]TiB2. There is a change from fully dendritic structure of the α-Al of A357 to a rosette-type structure of TiB2/A357. Significant increases in proof stress and Young's modulus can be obtained at low TiB2 additions. There exist dislocation loops around neighboring TiB2 particles with about 0. 1ηm in diameter and dislocation multiplication near TiB2 particles.
FEM NUMERICAL SIMULATION OF THE SOFT MEDIUM TUBE EXPANSION PROCESS
JL Song,W W Wang Taiyuan Heavy Machinery Institute,Taiyuan,China,
J.L. Song and W. W. Wang Taiyuan Heavy Machinery Institute
,Taiyuan,China

金属学报(英文版) , 2000,
Abstract: In this paper the soft medium tube expanding process of different loading case and tube sheet structure is simulated with FEM. The expanding patterns under different conditions are obtained. The correction of the Single-tube Model is verified, and cor- responding procedures are also proposed to correct the error.
TRANSFORMATION INDUCED SUPERPLASTICITY IN 18Ni MARAGING STEEL
YIN Zhongda Harbin Institute of Technology,Harbin,ChinaZHOU Yongkang Shanghai Centrifugal Machinery Research Institute,Shanghai,China,
YIN Zhongda Harbin Institute of Technology
,Harbin,China ZHOU Yongkang Shanghai Centrifugal Machinery Research Institute,Shanghai,China

金属学报(英文版) , 1992,
Abstract: After exploring the influence of stress,cold-rolling reduction and cooling rate on transforma-tion induced strain,the transformation induced superplasticity forming technique of the 18Nimaraging steel(2450 MPa)was developed.Through 14 times γα′ cyclic transformation,thelimited elongation of 320% can be obtained in 60% cold-rolled specimen.TEM observationrevealed that the morphology of stress induced martensite is massive.
RECRYSTALLIZATION-INDUCED PLASTICITY PHENOMENON IN 18Ni MARAGING STEEL UNDER ELASTIC STRESS
18Ni合金在弹性应力作用下再结晶诱发塑性现象

YIN Zhongda,ZHOU Yongkang Harbin Institute of Technology Shanghai Centrifugal Machinery Research Institute YIN Zhongda,Pacxlty of Heat Treatment of Materials Harbin Institute of Technology,Harbin,
尹钟大
,周永康

金属学报 , 1989,
Abstract: The phenomenon of recrystallization-induced plasticity (RIP) in thecold-rolled (40-70% reduction) 18Ni maraging steel under elastic stress on heatingwas observed in research for the superplasticity during cyclic phase transformation.An approach to the RIP process has been made by the analysis of dynamic behav-iour of the alloy at elevated temperature, the phenomenological analysis of dynamicstrain feature curves, the confirmation of phase transformation point and TEM ob-servation of RIP processing itself.
EFFECT OF DUCTILE-BRITYLE TRANSITION TEMPERATURE OF Al-Si COATING ON FATIGUE PROPERTIES OF Ni-BASE SUPERALLOYS
ZHANG Detang Beijing Institute of Aeronautical Materials,Beijing,China Beijing Institute of Aeronautical Materials,Beijing,China,
ZHANG Detang Beijing Institute of Aeronautical Materials
,Beijing,China Beijing Institute of Aeronautical Materials,Beijing,China

金属学报(英文版) , 1990,
Abstract: The effect of Al content on the ductile-brittle transition temperature of Al-Si coating and the effect of fracture behaviour.of the Al-Si coating on the fatigue properties of Ni-base superallovs have been investigated to propose the theoretical basis of search for an optimum of mechanical properties of the high temperature coating on Ni-base alloys.
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