AZ91镁合金在冷却系统中的耐腐蚀性

运用电化学方法研究一种水杨酸Schift 碱化合物(Salcn)对AZ91镁合金在30%乙二醇水溶液(30%EG/W)中的腐蚀行为的抑制作用。用扫描电镜观察合金在30%乙二醇水溶液(30% EG/W)中的腐蚀前、后的形貌。在室温下,添加这种水杨酸Schift碱化合物对AZ91镁合金的腐蚀抑制作用不明显,但在高温下,由于合金表面化学吸附了抑制剂而使其耐腐蚀性得到增强;随着抑制剂浓度的增加,镁合金表面吸附更多的抑制剂,从而使抑制作用的增强。     

Improving the Quality of Thermocouple Wire Made of Platinum-rhodium Alloys

For the manufacture of S-type thermocouple the so-called thermocouple wire of platinum and platinum-rhodium alloy is used.One of the main technical requirements for the quality of the wire,according to State Standard of Russia(GOST 10821),is the uniformity of its largest thermoelectric force(Thermo-emf) in the length different sections.It was found that a determining impact on the uniformity of the wire thermo-emf is the distribution of rhodium along the length of the wire.The impact of platinum-rhodium melt crystallization conditions on the inhomogeneity of wire manufactured from it.It was suggested that the chemical inhomogeneity of the wire is related to the liquation phase of platinum-rhodium alloy.     

STUDY ON COMPOSITION, MICROSTRUCTURE AND HARDNESS OF DLC FILMS BY VCAD

DLC super-hard films have been deposited on the substrates of single crystalline Si, pure Ti and stainless steel 18-8 by a method of vacuum cathode arc deposition (VCAD). The composition, microstructure and micro-hardness of the films have been studied in this paper. The results indicate that hardness of the DLC films is different on the different substrates. Hardness of the films increases with decreasing in surface roughness of the films. The maximum value of micro-hardness belongs to the DLC films deposited under the hydrogen pressure of 0.35Pa and the negative bias of 100V.     

改善“最终形状成形”的经济性

改善“最终形状成形”的经济性美国国民机械公司ＲｏｂｅｒｔＪ．ＳｃｈｉｌｉｎｇＷｉｌｉａｍＲ．Ｐｅｒｒｙ１“接近最终形状成形”的优越性利用多模递进式成形机由金属盘料来冷锻生产零件已被广泛接受。这种加工与切削、铸造或锻造等相比较具有下列明显的优点：①降低...     

热芯盒制芯原材料及工艺参数的探讨

介绍了株洲电力机车厂进口的意大利热芯盒射芯机调试及正常生产所用树脂砂的原材料的优选,包括原砂的选用、催化剂种类及最佳配比、树脂的选择及加入量,并介绍了制芯工艺参数的选择。     

DIELECTRIC PROPERTIES OF NANO Si/C/N COMPOSITE POWDER AND NANO SiC POWDER AT HIGH FREQUENCIES AND MICROSTRUCTURE CHARACTERIZATION

１．ＩｎｔｒｏｄｕｃｔｉｏｎＮａｎｏｍａｔｅｒｉａｌｓａｒｅｉｎｃｒｅａｓｉｎｇｌｙｒｅｃｅｉｖｉｎｇｒｅｃｏｇｎｉｔｉｏｎａｓｐｒａｃｔｉｃａｌｓｔｒｕｃｔｕｒａｌａｎｄｆｕｎｃｔｉｏｎａｌｍａｔｅｒｉａｌｓｗｉｔｈｇｏｏｄｐｒｏｓｐｅｃｔ,ａｎｄｈａｖｅｂｅｅｎｄｅｖｅｌｏｐｅｄｅｘｔｅｎｓｉｖｅｌｙｉｎｒｅｃｅｎｔｙｅａｒｓ．ＴｈｅｎａｎｏＳｉ／Ｃ／ＮｃｏｍｐｏｓｉｔｅｐｏｗｄｅｒａｎｄｎａｎｏＳｉＣｐｏｗｄｅｒｈａｖｅｒｅｃｅｉｖｅｄａｎｉｎｃｒｅａｓｉｎｇｉｎｔｅｒｅｓｔｓｉｎｃｅｔ…     

溅射气氛中O2／Ar比及热处理对直流反应磁控溅射法制备玻璃基TiO2薄膜结构与亲水性的影响

在工作气压为0．80Pa的氧氩气混合气氛下，改变氧与氩的流量比(O2／Ar：0．10，0．20，0．30)，在预先镀10nm左右SiO2的普通玻璃基片上用直流(D．C．)磁控溅射法制备了300nm左右的TiO2薄膜试样。离线在500℃、氧气氛下对试样热处理2h。用X射线光电子能谱(XPS)和X射线衍射仪(XRD)分别研究了试样热处理前后的表面元素组成、离子状态和物相组成，用接触角分析仪测试了试样在紫外光(UV)照射后的水润湿角。     

Wetting kinetics of SiC nanoparticle reinforced Sn-Pb eutectic solders

SiC nanoparticles reinforced eutectic Sn-Pb solder were prepared by mechanical mixing method. Reactive wetting of the resultant composite solders on Cu substrates was investigated using real time, in-situ visualization of the triple-line movement. It was found that spreading rates of all solder pastes in this work do not obey Tanner's law of non-reactive spreading. SiC nano-particles slow down both the pre-melting and post-melting spreading rates of composite solder pastes. As the content of SiC nano-particles increase, the melting point of composite solders decrease, and the spreading time of molten composite solder pastes increases.     

纳米复合Ti-B-N薄膜的结构和摩擦学性能

研究了射频等离了体辅助化学气相沉积（PCVD）技术获得的Ti-B-N薄膜的组织结构和力学性能。结果发现，B元素的加入使薄膜中出现TiN纳米晶和BN非晶（nc-TiN／a-BN）的复合结构，其硬度显著高于TiN薄膜，最高可达40GPa。用球盘式摩擦磨损实验考察了薄膜的磨损特性。结果表明：与TiN薄膜相比，Ti-B-N薄膜抗磨损性能有显著提高，磨损机制与TiN薄膜不同，摩擦系数较TiN稍高。     

NUMERICAL SIMULATION OF CASTING＇S MOLD FILLING PROCESS

Numerical simulation of casting＇s mold filling process is the main and the most important aspect of the foundry CAE technology. But it is time-consuming; it may take dozens of hours or several days. While with the development of computer hardware, numerical simulation of casting＇ s mold filling process has made rapid progress. The simulation results, therefore, have become more and more practical. This study tries to find some clues of the computational time of mold filling process. Firstly, this paper introduces mathematic model and the basic route of numerical simulation of casting＇s mold filling process. Then the computational time of mold filling process has been carefully studied, and some new and useful results have been gained from the study of the computational time. Finally, this paper has given some real applications of numerical simulation of casting＇s mold filling process.