锯齿状魏氏组织表面浮凸的扫描隧道显微镜研究

用扫描隧道显微镜观察到Ｆｅ－０．３７Ｃ（质量分数％）风中的锯齿状魏氏组织产生表面浮凸,发现其浮凸是由多片魏氏组织片条组的浮凸群,浮凸高度约为６０－１７０ｍｍ,低于其形核处仿晶型铁素体的表面浮凸,在仿晶型铁素体中观察到面－面激发形核方式,其浮凸的最大形状变形量为０．３９,锯齿状魏氏组织和仿晶型铁素体的表面浮凸可用台阶机制解释,并以台阶机制定性解释了帐篷型,复杂型和单倾型表面浮凸的形成过程。     

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...     

DIRECTIONAL COARSENING OF THE γ'-PHASE DURING COMPRESSION CREEP OF A SINGLE CRVSTAL NICKEL-BASE SUPERALLOY

对「００１」取向单晶镍基合金恒温恒载压缩蠕变不同时间的组织形貌进行了ＳＥＭ和ＴＥＭ观察表明：蠕变初期,两立方γ‘相沿平行于应力轴方向扩散相连定向生长成为条形筏结构;垂直通道中基体「００１」晶向共格应变量减小,应变能降低是合金元素定向扩散形成γ’相符结构的驱动力;压缩与拉伸蠕变相比较,γ’相形筏所需要的时间较长,应力较大。     

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...     

Monitoring Computer Numerical Control Machining Progress Based on Information Fusion

To cope with the market demand dynamically,enterprise needs to obtain the production status of work in process real-timely,but the information of machining progress has feature of uncertainty and can not reflect the status of production field effectively.In this work,to overcome the ineffectiveness of computer numerical control(CNC) machining progress information extraction and its application restriction in practice because of heterogeneous system of CNC machine,based on information fusion by analyzing multi-sources information,estimating CNC machining status and predicting the machining progress through tracking tool coordinates,a CNC machining progress monitoring method is presented.The multi-sources heterogeneous information includes machining path,real-time spindle power information,manual input data and tool position.On the method of obtaining this multi-sources heterogeneous information,the method which helps explore numerical control(NC) program,monitor spindle power of CNC,collect human-computer interaction(HCI) information,obtain real-time tool coordinates and express the knowledge concerned in this field is analyzed;The decision rule of CNC machining status in the way of fusing multi-sources information in manufacturing process is summarized,as well as the machining progress tracking method in accordance with real-time tool coordinates and machining path is presented.Finally,the method discussed is proved feasible by the verification of machining progress tracking through simulation experiment.The proposed research realizes the effective integration of CNC machining progress information,and enables enterprises an efficient way to share CNC information and configure CNC resources optimally.     

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.     

I-beam Crack Identification Based on Study of Local Flexibility due to Crack

Local flexibility of crack plays an important role in crack identification of structures.Analytical methods on local flexibility in a cracked beam with simple geometric crossing sections,such as rectangle,circle,have been made,but there are some difficulties in calculating local flexibility in a cracked beam with complex crossing section,such as pipe and I-beam.In this paper,an analytical method to calculate the local flexibility and rotational spring stiffness due to crack in I-beam is proposed.The local flexibility with respect to various crack depths can be calculated by dividing a cracked I-beam into a series of thin rectangles.The forward and inverse problems in crack detection of I-beam are studied.The forward problem comprises the construction of crack model exclusively for crack section and the construction of a numerically I-beam model to gain crack detection database.The inverse problem consists of the measurement of modal parameters and the detection of crack parameters.Two experiments including measurement of rotational spring stiffness and prediction of cracks in I-beam are conducted.Experimental results based on the current methods indicate that relative error of crack location is less than 3%,while the error of crack depth identification is less than 6%.Crack identification of I-beam is expected to contribute to the development of automated crack detection techniques for railway lines and building skeletons.     

MICROWAVE-ASSISTED CARBOTHERMIC REDUCTION OF ILMENITE

ＭＩＣＲＯＷＡＶＥ－ＡＳＳＩＳＴＥＤＣＡＲＢＯＴＨＥＲＭＩＣＲＥＤＵＣＴＩＯＮＯＦＩＬＭＥＮＩＴＥＨＵＡＹｉｘｉｎａｎｄＬＩＵＣｈｕｎｐｅｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＭｅｔａｌｌｕｒｇｙ,ＫｕｎｍｉｎｇＵｎｉｖｅｒｓｉｔｙｏｆＳｃｉｅｎｃｅａｎｄＴ...     

EFFECT OF TRACE ELEMENTS WITH ZERO SELF－INTERACTIONCOEFFICIENT ON CRYSTALLIZATION TEMPERATUREOF IRON CARBON ALLOYS

ＥＦＦＥＣＴＯＦＴＲＡＣＥＥＬＥＭＥＮＴＳＷＩＴＨＺＥＲＯＳＥＬＦ－ＩＮＴＥＲＡＣＴＩＯＮＣＯＥＦＦＩＣＩＥＮＴＯＮＣＲＹＳＴＡＬＬＩＺＡＴＩＯＮＴＥＭＰＥＲＡＴＵＲＥＯＦＩＲＯＮＣＡＲＢＯＮＡＬＬＯＹＳＺＨＡＩＱｉｊｉｅａｎｄＨＵＨａｎｑｉ（Ｄｅｐ...