层状固体润滑薄膜的研究进展

层状物固体润滑薄膜是固体润滑薄膜中最常用的形式.本文针对4种有代表性的层状物固体润滑薄膜(硫化亚铁、二硫化钼、石墨及二硫化钨薄膜)的制备方法及摩擦学性能进行了详细论述,这些薄膜都具有优良的减摩、耐磨、抗擦伤性能,但不同的薄膜其摩擦学性能有差异,适用工况也不尽相同.     

插座壳体注射模设计

介绍了插座壳体的成形工艺,提出了活动型芯块成型、内侧滑块脱模的模具结构,在分型面成型内侧凸台的同时,利用活动型芯块降低脱模力,解决了内侧滑块多、顶出机构不易设置、脱模过程容易夹腔的问题。模具结构简单,可靠性高,模具寿命也大幅度提高。     

高速机床进给系统的发展趋势

在明确了高速加工对机床进给进给系统要求的基础上，比较和分析了滚珠丝杠、直线电机和并联虚拟轴机构等三种高速进给系统的性能、特点、存在问题及其解决办法，指出了它们各自的适用范围和应用前景。     

FLOTATION MECHANISM OF FLUORITE AND HEMATITE WITH SODIUM NAPHTHENE SULFONATE

ＦＬＯＴＡＴＩＯＮＭＥＣＨＡＮＩＳＭＯＦＦＬＵＯＲＩＴＥＡＮＤＨＥＭＡＴＩＴＥＷＩＴＨＳＯＤＩＵＭＮＡＰＨＴＨＥＮＥＳＵＬＦＯＮＡＴＥ￥Ｇｅ，Ｙｉｎｇｙｏｎｇ；Ｑｕｅ，Ｘｕａｎｌａｎ（ＣｈａｎｇｓｈａＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＭｉｎｉｎｇ...     

反应等离子喷涂TiN/AlN涂层在润滑状态下摩擦磨损性能的研究

对用反应等离子喷涂法制备的TiN/AlN涂层在油润滑条件下的摩擦磨损特征进行了研究,并就轻、重载荷下的磨损机理进行了探讨。结果表明:油润滑条件下,涂层磨损体积显著降低。在轻载荷下,以疲劳磨损为主;在重载荷下,以脆性剥落和磨粒磨损为主。     

纳米TiO2-SnO2复合薄膜的光生阴极保护作用及机理研究

用溶胶-凝胶法和旋转涂膜技术在导电玻璃(ITO)表面构筑纳米TiO2膜和纳米TiO2-SnO2复合膜,应用AFM、XRD对膜的形貌及晶体结构进行表征.用光电化学和腐蚀电化学相结合技术,通过测试时间-电位曲线和交流阻抗谱研究光生阴极保护状态下316L不锈钢电极在0.5 mol/L NaCl溶液中的微观界面电荷分布及电子传递规律,探讨光生阴极保护的作用机理.结果表明以TiO2-SnO2复合膜作为光生阳极时,在紫外光照下,316L不锈钢电极可处在阴极保护状态,并且在切断光源后,光生电极电位仍可在较长的一段时间内维持在-0.2 V左右,仍具有一定的阴极保护作用.     

Anti-oxidation mechanism of SiC-B4C-C composites

Mixture of green petroleum coke, B4 C and SiC together with short carbon fiber were employed as starting materials, the mixture was press formed without any binder after grinding, dense and homogeneous binderless SiC-B4 C-C（carbon/ceramic） composites were then obtained after sintering. Composites thus prepared possess excellent anti-oxidation property, that is, mass loss less than IG within the temperature range from 900 to 1 100 ℃ for 10 h. Anti-oxidation mechanism was also discussed from the viewpoint of thermodynamics, excellent anti-oxidation property of materials thus prepared can be discribed to 1） solid SiO2 formed from SiC, which restrains the filtering of oxygen and simultaneously, its volume expansion brought about by the reaction takes roles both walling up the original pores and making the material more compact; 2） liquid B2O3 from the reaction of B4C not only makes the combination with C, B4 C and SiC tighter through forming solid solution, but also effect of reaction SiC（s）＋2CO（g） =SiO2 （s）＋3C（s） is an expansive process, which improves the microstructure of the material.     

Modification mechanism of cerium on the Al-18Si alloy

The effect of the rare earth cerium （Ce） on the hypereutectic Al-Si alloy under different casting states have been studied by optical microscope and quantitative image analysis. It is found that the size and the quantity of primary silicon in castings decrease with the increase of added Ce in the melt. Meanwhile primary silicon changes from branched shape to fine facetted shape. Although the modification on eutectic silicon in castings also improves with the increase of added Ce in the melt, the effect of modification on eutectic silicon away from primary silicon is more obvious than that on eutectic silicon close to primary silicon. The modification mechanism was analyzed in detail by means of scanning electron microscope equipped with energy dispersive analysis of X-ray and thermodynamics analysis, which included the analysis on the change in standard Gibbs energy of reaction and reaction equilibrium.     

TaC涂层的氧化特征与氧化机制

用在空气中氧化、氧炔焰超高温烧蚀等方法对TaC涂层在不同温度的氧化特征与氧化机制进行研究。研究结果表明：TaC在508℃以上开始氧化,在508～690℃时氧化产物为六角Ta2O3固溶体,690～900℃时氧化产物转化为斜方Ta2O5晶体,900～1500℃时氧化产物为斜方Ta2O5,其形态为龟裂或多孔烧结态,未能形成对TaC的隔离保护膜;1500℃氧化时出现部分Ta2O5液相与Ta2O5斜方相共存的现象;在氧炔焰超高温2300℃烧蚀时形成大量的Ta2O5熔体液膜,熔体与TaC的润湿性很好。TaC涂层由低温无熔体情况下界面反应控制机制变为氧通过熔体溶解与扩散的控制机制。     

含石墨镍铬基合金的高温氧化行为

利用热重分析法、X射线衍射法和扫描电镜研究了不同石墨含量(0%、3%、6%、9%)镍铬基高温合金在800℃、900℃和950℃下的高温氧化行为。合金在石墨含量较低,800℃、900℃氧化时,氧化增重基本遵循抛物线规律,表面氧化膜无剥落,在950℃氧化时表面氧化膜出现剥落,近似直线规律。900℃氧化时,含石墨0%、3%的合金氧化膜由Cr2O3和NiCr2O4组成。根据氧化膜的组成分析了合金的氧化机理。