材料期刊网

AN IRREVERSIBILITY PHENOMENA IN ELECTRICAL CONDUCTIVITY OF THE MELTS IN SODIUM IRON PHOSPHATE SYSTEM

F. Y. Chen1)and E. D. Delber2) 1) State Key Laboratory of Solidification Process , Northwestern Polytechnic University , Xi’an 710072 , China 2) Department of Ceramics Engineering , University of Missouri Rolla , Rolla , Mo 654301 , USA

金属学报(英文版)

Theelectricalresistivityofsodium iron phosphate melts wasinvestigated asa functionoftem peratureand composition. Irreversibility was found in thetemperature dependent electricalresistivityinthe melts withlow Na2 Ocontentduringtheheating andcoolingcycle. Theirre versibility wasreduced withincreasing Na2 Ocontent. Theelectricalresistivity tendedto de creaseslightly withtime. Theelectricalconduction ofthe meltscontainingsimulatedindustry waste wassimilartothatofthe melts withsimilarsodacontent. Thetemperature dependent electricalresistivity and activation energy ofthese melts was discussed using the Motttheory and wascorrelatedtothe Fe(II) contentinthe melts

关键词: irreversibility , null , null

PREDICTION OF PATH-DEPENDENT FAILURE IN ALUMINUM SHEET METALS UNDER FORMING OPERATIONS

H.-M. Huang , J. Pan and S. C. Tang 1) Mechanical Engineering and Applied Mechanics , The University of Michigan Ann Arbor , MI 48109 , USA 2) Ford Research Laboratory , Ford Motor Company Dearborn , MI 48121 , USA

金属学报(英文版)

An approximate macroscopic yield criterion for anisotropic porous sheet metals is adopted in a failure prediction methodology that can be used to investigate the failure of sheet metals under forming operations. This failure prediction methodology is developed based on the Marciniak-Kuczynski approach by assuming a slightly higher void volume fraction inside randomly oriented imperfecte analysis. Here, a nonproportional deformation history including relative rotation of principal stretch directions is identified in a selected critical element of an aluminum sheet from a FEM fender forming simulation. Based on the failure prediction methodology, the failure of the critical sheet element is investigated under the non-proportional deformation history. The results show that thiven non-proportional deformation history.

关键词: sheet metal forming , null , null , null

The Application of Pattern Recognition to the Formability of Quasicrystal Formation in Al-alloys

LUO Xuecai , CHENG Zhaonian , CHEN Nianyi , PAN Yugang Shanghai Institute of Metallurgy , Academia Sinica , China. Boston College , USA

材料科学技术（英）

关键词:

THREE-DIMENSIONAL MATHEMATICAL MODELING OF TRANSPORT PROCESSES IN CVD REACTORS

HE Youduo , Baotou Institute of Iron and Steel Technology , Baotou , ChinaY.SAHAI , The Ohio State University , USA

金属学报(英文版)

A mathematical model to represent the fluid flow, temperature distribution and mass transfer in CVD reactors has been developed. The model is used to predict the velocity, temperature, and molar concentration profiles in the tapered annulus of a reactor for silicon deposition from SiCl_4 in H_2. Results of the investigation contribute to the understanding of the transport pro- cesses involved in such a system. The model can also be used for optimizing the design parameters, such as inlet flow rate, susceptor tilt angle, etc.

关键词: reactor of chemical vapor deposition , null , null , null