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161.
目前,对于棒材和坯料尺寸还没有普遍实行测定。但在不久将来,随着生产的提高,快速轧机的建立,以及轧制工艺自动化的实现,测定它们的尺寸,对于达到理想的轧机性能,将必不可少。为此,采用自动仪表进行测定,非常必要。本文对这些测定方法及仪表进行了综合性的概要说明。在谈到接触式或非接触式测定方法时,重点放在非接触式方法上,因为后者特别适合于上述特殊场合。现在各种物理测量原理,如X和γ射线的吸收、影象技术、微波、涡流、以及光学方法(从影象强度比较到各种扫描系统),都成功地得到了应用。本文还讨论了各种几何图形的 相似文献
162.
163.
DEVELOPMENT OF NEW THERMO-MECHANICAL SIMULATOR 总被引:1,自引:0,他引:1
Z.G.Luo H.L.Su D.H.Zhang G.D.Wang X.H.Liu 《金属学报(英文版)》2004,17(1):33-37
A new multifunction thermo-mechanical simulator was successfully developed. The accuracy of measurement and control is very high through all digital control. More than twenty tests may bc fulfilled including tension, compression, torsion combination large deformation that meets the study of supersteel,etc.Its performance is introduced in the paper,such as designed ideas, machine structure,man-machinc interface, control system, etc. 相似文献
164.
Z.L.Chang J.L.Song N.H.Hao 《金属学报(英文版)》2004,17(1):61-63
Equal cross section lateral extrusion (ECSLE) is an effective method realizing pure shear deformation.The influence of friction factor on the deformation uniformity of ECSLE was investigated with rigid plastic finite element method.The result shows that the non-uniform deformation in extrusion is caused mainly by the friction between workpiece and die.The higher the friction factor is.the more uneven plastic deformation resulted in extruded workpiece.The relation curve of deformation uniformity vs. friction factor was drawn based on the analysis result. The curve can be used as a basis of ECSLE process design. 相似文献
165.
X.H.You F.Wang L.C.Wang 《金属学报(英文版)》2004,17(3):279-282
A new technique, powder compact foaming process for the production of aluminum foams has been studied in this article. According to this method, the aluminum powder is mixed with a powder foaming agent (Till2). Subsequent to mixing, the powder blend is hot compacted to obtain a dense semi-finished product. Upon heating to temperatures within the range of the melting point, the foaming agent decomposes to evolve gas and the semi-finished product expands into a porous cellular aluminum. Foaming process is the key in this method. Based on experiments, the foaming characteristics were mainly analyzed and discussed. Experiments show that the aluminum-foam with closed pores and a uniform cell structure of high porosity can be obtained using this method by adjusting the foaming parameters: the content of foaming agent and foaming temperature. 相似文献
166.
Due to complexities of draw-bead restraining force calculated according to theory and depending on sheet metal forming properties experiment testing system, a simplified method to calculate draw-bead restraining force is put forward by experimental method in cup-shaped drawing process. The experimental results were compared with numerical results and proved agreement. It shows the method is effective. 相似文献
167.
T. Yang B.H. LiDepartment of Materials Physics University of Science Technology Beijing Beijing ChinaK. Kang T. SuzukiInformation Storage Materials Laboratory Toyota Technological Institute Nagoya - Japan 《金属学报(英文版)》2003,16(4):261-265
(FePt/Ag)n nano-multilayers were deposited on MgO (100) single crystal with laser ablation and then subjected to annealing. FePt L1o grains with (001) texture and thus a large perpendicular magnetic anisotropy constant Ku of the order of 106 J/m3 were formed. A thick Ag layer is found to be favorable for decreasing the dispersion of the easy axis for magnetization. The measurement of time decay of magnetization gave rise to a small activation volume of the order of 10-25m3, showing the promising of being the recording medium for future high density perpendicular recording. 相似文献
168.
STUDY ON Ni-Cr SYSTEM SOLAR SELECTIVE THIN FILMS PREPARED BY MAGNETRON REACTIVE SPUTTERING PROCESS 总被引:1,自引:0,他引:1
B. W. Wang H. Shen Guangzhou Institute of Energy Conversion The Chinese Academy of Sciences Guangzhou China 《金属学报(英文版)》2002,15(2):203-206
1. IntroductionSolar selective thiIl solid fil1us are the key part for solar heat collect'ors. But ll1ostfactories still produced solar absorptive filn1s by traditional tecIl11ology sucl1 as pai1ltillga1ld electrocl1eluical process that nlust result in po… 相似文献
169.
H. Y. Zhao H. Wang Q.J. Liu J.D. Kan Z.Q. LiuDepartment of Materials Science Engineering Yunnan University Kunming China 《金属学报(英文版)》2002,15(5):431-438
Shock wave and annealing crystallization of amorphous alloys FeSiB, FeMoSiB and FeCuNbSiB were studied by isothermal and non-isothermal DSC technique. It was found that the shock wave crystallization is very perfect, the fraction crystallized is very close to 100%, though the period of crystallization is very short, only about 10-4-10-6s. Their produced phases differ from the parent phase in structure and composition. The high velocity of the transformation is very difficult to explain by the diffusion theory of solid state phase transition. 相似文献
170.
1.~nonNUInericalmodellingbythefiniteelement(FE)methodhasbecomeaneffectiveandeconomyicmeansforsimulatingmetalfoeingprocesses.However,accuratemodellingdemandsthecorrectdefinitionandinputsofthedataforthethermalandphysicalpIDPertiesoftheworkpieceandtoolmaterials,theboUndaryconditionsattheworkpiece--toolinterfaceandinotherareas,inadditiontoappropriatemeshgenerationandnumericalsolutions.Althoughmostofthematerialdataareavailable,thedataforinterfacialheattransferandfrictionconditions,Whichhavesubst… 相似文献