THE EFFECT OF SILICON ADDITIVE ON THESTRUCTURE AND PROPERTIES OFC－B_4C－SiC COMPOSITE

ＴＨＥＥＦＦＥＣＴＯＦＳＩＬＩＣＯＮＡＤＤＩＴＩＶＥＯＮＴＨＥＳＴＲＵＣＴＵＲＥ　ＡＮＤＰＲＯＰＥＲＴＩＥＳＯＦＣ－Ｂ_４Ｃ－ＳｉＣＣＯＭＰＯＳＩＴＥＨＵＡＮＧＱｉｚｈｏｎｇ;ＹＡＮＧＱｚａｏｑｉｎａｎｄＷＵＬｉｊｕｎ（ＰｏｗｄｅｒＭｅｔａｌｌｕｒｇ?..     

NANOCRYSTALLINE STRUCTURE AND INITIAL PERMEABILITY OF ANNEALED Fe_（73．5）Cu_1W_3Si_（13．5）B_9 Alloy

ＮＡＮＯＣＲＹＳＴＡＬＬＩＮＥＳＴＲＵＣＴＵＲＥＡＮＤＩＮＩＴＩＡＬＰＥＲＭＥＡＢＩＬＩＴＹＯＦＡＮＮＥＡＬＥＤＦｅ_（７３．５）Ｃｕ_１Ｗ_３Ｓｉ_（１３．５）Ｂ_９ＡｌｌｏｙＺＨＡＮＧＸｉａｎｇｙｉ,ＺＨＡＮＧＪｉｎｇｗｕａｎｄＺＨＥＮＧＹａｎｇｚｅ?..     

COMPOSITION AND SPECTROSCOPIC STUDIES OF HYDRATED SODIUM ALUMINATE COMPOUNDS

ＣＯＭＰＯＳＩＴＩＯＮＡＮＤＳＰＥＣＴＲＯＳＣＯＰＩＣＳＴＵＤＩＥＳＯＦＨＹＤＲＡＴＥＤＳＯＤＩＵＭＡＬＵＭＩＮＡＴＥＣＯＭＰＯＵＮＤＳＱＩＵＧｕｏｆａｎｇ,ＤＥＮＧＨｏｎｇｍｅｉ,ＺＥＮＧＷｅｎｍｉｎｇａｎｄＣＨＥＮＨｉａｎｙｉ（ＳｈａｎｇｈａｉＩ...     

IN SITU TEM STUDY ON THE R-PHASE TRANSFORMATION IN TiNi ALLOY

ＩＮＳＩＴＵＴＥＭＳＴＵＤＹＯＮＴＨＥＲ－ＰＨＡＳＥＴＲＡＮＳＦＯＲＭＡＴＩＯＮＩＮＴｉＮｉＡＬＬＯＹＣＨＥＮＱｉｎｇ;ＷＵＸｉｎｇｆａｎｇａｎｄＣ．Ｊ．Ｈｕｍｐｈｒｅｙｓ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＰｈｙｓｉｃｓ,Ｕｎｉｖｅｒｓｉｔ...     

Layout Planning Technology of Cellular Manufacturing System Based on Process Interconnection Analysis

With sustaining change of production mode,layout planning is no longer a thing built once for all.Cellular layout(CL) is becoming a hotspot in the research field of manufacturing system layout.Traditional researches on layout planning are mainly concentrating on aspects of layout arithmetic,style and evaluation,etc.Relatively seldom efforts are paid to CL and its specific problems as cell formation(CF),equipment sharing and CL analysis.Through problem analyzing of layout in cellular manufacturing system(CMS),research approach of cell formation,interactive layout and layout analysis threaded with process interconnection relationship(PIR) is proposed.Typical key technologies in CL like CF technology based on similarity analysis of part processes,interactive visual layout technology,layout evaluation technology founded on PIR analysis and algorithm of cell equipment sharing are put forward.Against the background of one enterprise which encounters problems of low utility of key equipments and disperse material logistic,an example of four-cell layout is given.The CL adjustment and analysis results show that equipment with high level of sharing degree should be disposed around the boundary of its main cell,and be near to other sharing cells as possible;process route should be centralized by all means,so equipment adjustment is to be implemented along direction that route intersection can be decreased;giving consideration to the existence of discrete cell,logistic route and its density should be centralized to cells formed.The proposed research can help improve equipment utility and material logistic efficiency of CL,and can be popularized to other application availably.     

Vibro-acoustic Radiation Characteristics Analysis of Railway Vehicle Wheel with Damping Ridges Based on Modal Strain Energy

The existing researches on the damping wheel mainly focus on investigating the influence of damping structure change on the vibro-acoustic control.The changes include the geometric size of the damping structure,the damping material parameters,and the placement,and so on.In order to further understand the mechanism in reducing the acoustic radiation of railway wheel with layer damping treatment,in this paper,the wheel is simply modified by a full-sized circular plate.The circle plate side has stuck circumference constrained damping ridges and radial constrained damping ridges on it.Based on a hybrid finite element method-boundary element method(FEM-BEM),the paper develops a vibro-acoustic radiation model for such a distributed constrained damping structure.The vibration and acoustic radiation of the circular plate is analyzed.In the analysis,the dynamic response of the system is obtained by using the 3D finite model superposition method.The obtained vibration response is used as the initial boundary condition in solving Helmholtz boundary integral equation for the sound radiation analysis.In the procedure,firstly,the modal analysis of the circular plate is performed to get the distribution of the system modal strain energy.Secondly,the vibro-acoustic radiation characteristics of the plate with different kinds of circumference damping ridges and radial damping ridges are compared in order to try to find the best effective damping ridge structure.Thirdly,using the distribution of the plate modal strain energy investigates the effect of the ridge distribution locations on the circular plate on its vibro-acoustic radiation.The calculation and analysis research results show that,the sticking circumference and radial damping ridges on the plate can control the vibro-acoustic radiation of the plate effectively in different frequency range.The distribution of the constrained damping ridge has an effect on reduction in vibro-acoustic radiation of the circular plate.The present research is very useful in the design of railway wheel with low noise level.     

Application of Nd:YAG Laser Welding to Implantable Neuro-Stimulator

It is difficult to weld the material and structure of implantable neuro-stimulator such as pure medical titanium and irregular outside shield by conventional arc welding methods.Currently there are few reports on the neuro stimulator sealing technology,and none of them have simultaneously considered the quality control methods.In order to develop the sealing procedure and quality control methods,an investigation of applying Nd:YAG laser welding to implantable neuro-stimulator components is carried out.Firstly,the automatic Nd:YAG laser welding system equipped with proper fixture configuration is introduced.A special fixture structure is illustrated and the key point for the device is to reduce the fit-up gap between the two shields.Then,a novel welding process technique is proposed to satisfy the engineering requirements.The optimized process parameters for titanium shell,feedthrough and fastener are provided and concluded by an orthogonal experiment.Finally,different quality control measures such as visual inspection,X-ray detecting and leakage testing,are presented on the final products.The results show that the Nd:YAG laser welding applied on the implanted neuro-stimulator under optimized parameters can prevent welding defects and improve the weld joints quality.Combination of various quality control methods will guarantee the sealing performance and mechanical properties of the products.It is confirmed that the processing procedure and quality methods can not only resolve the process technology on welding ultra-thin structure of medical device,but also provide the reference for other implantable device.     

Accelerated Degradation Reliability Modeling and Test Data Statistical Analysis of Aerospace Electrical Connector

As few or no failures occur during accelerated life test,it is difficult to assess reliability for long-life products with traditional life tests.Reliability assessment using degradation data of product performance over time becomes a significant approach.Aerospace electrical connector is researched in this paper.Through the analysis of failure mechanism,the performance degradation law is obtained and the statistical model for degradation failure is set up;according to the research on statistical analysis m...