Interfacial microstructure of 20% SO2/Al matrix composites reinforced with in situ formation ceramic phases

Al matrix composites reinforced with in situ ceramic phases by adding 20% SiO2 were fabricated by powder metallurgy process.The interfacial microstructure of the composites was studied by means of SEM and HREM.It was shown that the ceramic phases mainly composed of spinel MgAl2O4 are formed in situ in the original SiO2 particle and the size of small MgAl2O4 crystallites is about dozens of nanometers,which can adjacent to Al and Si.MgO could not found in original SiO2 particle but a little in matrix and may exist with Si,Mg2Si and Al.Si is mostly distributed in matrix and forms some segregation zones.The size of Mg2Si is about 50-100nm and can usually be seen in the matrix.     

SiC（Cu）／Fe复合材料制备工艺研究

采用非均相沉淀法制得Cu包裹SiC复合粉体，利用粉末冶金和常压烧结制备SiC（Cu）／Fe复合材料。利用Zeta电位仪、XRD，EDS以及SEM等手段对包裹粉体和烧结样品进行了分析。结果表明，采用非均相沉淀法可以得到Cu／SiC复合粉体。包裹后的粉体与原始SiC粉体的表面电位不同，达到了对SiC颗粒表面改性的目的。Cu作为过渡层改善了SiC／Fe的界面相容性，在1050℃烧结的样品只有微量的FeSi或Fe2Si生成，界面反应得到有效控制，获得化学结合的界面，温度过低不能烧结致密，温度过高出现大量缺陷。     

TiNb（Y_2O_3）长纤维增强Ti－48Al－2Cr－2Nb合金复合材料的弯曲变形与界面

研究了ＴｉＮｂ（Ｙ２Ｏ３）连续纤维增强Ｔｉ－４８Ａｌ－２Ｇｒ－２Ｎｂ合金复合材料的界面及显微组织。研究发现：复合材料的弯曲强度比基体略有提高，弹性模量和挠度有所下降。在纤维和基体之间形成一层约１０～２０μｍ厚的α２－Ｔｉ３Ａｌ性层，近界面基体组织有片层化倾向。大量变形层错带和孪晶出现及界面位错墙的形成成为塑变及强化的主要机制。     

HEAT TRANSFER ANALYSIS DURING ROLLING OF THIN SLAB IN CSP

A mathematical model has been built to numerically predict the thermal history of thin slab during CSP （compact strip process） rolling. To estimate the temperature distribution in the slab mare accurately, the mathematical model combines heat transfer in the slab, in the roll, and at the roll-slab interface during bite. The numerical results agree with on-site running data, which proves the reliabili~, of the mathematical model. The results show that roll chilling has a significant effect on the temperature distribution in the slab.     

Al2O3/Al基复合材料与基体结合强度物理意义分析

测定了Al2 O3 /Al基复合材料与基体材料间的结合强度 ,探讨了结合强度的物理意义。其物理意义是 :界面抗拉强度与试样达到断裂应变时基体中的应力分别与纤维体积分数和基体体积分数的加权平均值。并根据测定的结合强度的值结合有限元分析得出几种Al2 O3 /Al基复合材料的界面抗拉强度值     

注射模CAE远程应用系统的研究与实现

研究了注射模CAE远程应用系统的实现方法。围绕建立最优系统模型 ,探讨了数据压缩算法和FTP文件服务 ,并采用主从服务器分离法提高系统性能。为进一步优化系统 ,运用了多线程、套接字、ADO和RAS远程拨号等技术。     

Sliding wear of non-hydrogenated diamond-like carbon coatings against magnesium

Magnesium alloys are of increasing interest to the automobile industry for their potential in reducing vehicle weight, and in turn, improving fuel economy and lowering emissions. It follows that improving the magnesium manufacturing processes will promote greater use of magnesium alloys in automobiles. In recent years, diamond-like carbon (DLC) coatings have attracted attention for their low coefficient of friction (COF) and wear rates. The implementation of DLC coatings on tool and die surfaces may help increase the efficiency of magnesium component manufacturing processes (such as cutting and sheet forming) and also improve the surface quality of the finished products.In this study, the dry sliding wear behaviour of magnetron sputtered non-hydrogenated DLC coatings against Mg (> 99.9 wt.%) was investigated using a vacuum pin-on-disc tribometer. Tests were performed in ambient air (28% RH) and in argon, under a constant load of 5 N and at a sliding speed of 0.12 m/s. In argon, the non-hydrogenated DLC coatings showed a very low COF of 0.05 after an initial running-in period. Carbonaceous material transfer from the non-hydrogenated DLC to the contact surface of the Mg pin was observed in argon. Changing the test atmosphere from argon to ambient air increased the COF to 0.40, which was accompanied by the formation of oxidized Mg debris and an increased wear rate. The friction and wear mechanisms of non-hydrogenated DLC coatings against Mg are proposed to rationalize experimental observations.     

"THERMO": COMPUTER PROGRAM FOR SIMULATION OF SURFACE PULSE HEATING

1.IntroductionTheoneofthemostimportantparametersofthethermalcycleduringsurfacepulseheatingistherateofheatingandcooling.Knowledgeofthesevaluesinparticulartemperatureintervalshelpstoprognosticatephasestructureintheheataffectedzones(HAZ),toanalyzecausesofthestructuretransformations.Todaythereisavoluminousliteratureoncalculationofthethermalconditionsforasolidduringsurfaceprocessing.Butthetemperaturevariationsareusuallyexaminedasafunctionoftimeorspacecoordinates.Sometimesthefirstderivativeofthete…     

自动线计算机图形监控系统的研究

介绍一种通过与PLC进行实时通讯，将自动线各部分工作状态动态地显示在计算机窗口界面上的图形化监控系统。该系统的运用，使整个加工过程的监控更为有效、直观。     

Effect of rinsing and drying on silicon surface cleaning for epitaxial growth

We investigated the effect of the rinsing and drying technique on the oxygen and carbon concentration on a silicon surface. Rinsing in deionized water increased the interfacial oxygen concentration and helped generate defects. Blow-drying was more efficient than spin-drying in reducing interfacial oxygen concentration. Exposure to the atmosphere was detrimental to obtaining high crystallinity in the epitaxial layer. We evaluated the effectiveness of the cleaning process by observing the grown epilayer and the epilayer/substrate interface.