调整粘结相和加Cr3C2对WC—10%Co硬质合金性能的影响

为了生产细晶粒和耐腐蚀的碳化钨（ＷＣ）基硬质合金，通常的做法是加入少量的碳化钨（Ｃｒ３Ｃ２）。然后，大量的Ｃｒ３Ｃ２（最高达６ｗｔ％）作为代替碳化钨加入的影响还没有作系统的研究，本文集中研究了ＷＣ－１０Ｃｏ硬质合金中，采用Ｃｒ３Ｃ２代替硬质相的影响，尝试了以Ｎｉ部分或全部地代替粘结金属钴的工作，试样使用标准的液相烧结方法制取，并对烧结孔隙度，机械性能，抗腐蚀性以及显微结构的参数进行了检验，结果证明     

The Friction and Wear Properties of CrN, Graphit-iC and Dymon-iC Coatings in Air and under Oil-lubrication.

NITRIDE COATINGS have always been the popularchoice for increasing the wear lifetime for industrialcomponents.TiN is the most widely accepted butrecently CrN has been gaining more interest due itsthermal stability and good performance in corrosiveenvironments.Knowledge of the tribologicalperformance of CrN coatings in dry and lubricatedconditions is still quite limited[1,2].Many authorshave studied the properties of diamond like carbon(DLC)films and how they perform in dry conditions[…     

STRUCTURAL DETERMINATION OF TITANIUM-OXIDE NANOPARTICLES BY X-RAY ABSORPTION SPECTROSCOPY

As a potential application of titanium-oxide nanoparticles, it is extremely important to investigate a detailed picture of the surface and interior structural properties of nanocrystalline materials, such as rutile and anatase with diameters 7.0 and 4.5nm, respectively. X-ray absorption spectroscopy has been used to identify the local Ti environment and related electronic structure. We combine the experimental results at the Ti edge in both bulk and nano-crystals to determine the lattice distortion in terms of differently characteristic preedge features and the variation in the multiple-scattering region of X-ray absorption near-edge structure (XANES) spectra. The relationship between the transition peaks and the surface-to volume ratio is also discussed.     

AN EXPERIMENTAL-NUMERICAL METHOD FOR MEASURING CRACK PROPAGATING VELOCITIES UNDER STRESS WAVE LOADING

An experimental-numerical method for measuring dynamic crack propagating velocities under stress wave loading is established in this paper. The experiments of the three-point bend specimen are done on the improved Hopkinson bar. Deflection of loading point, dynamic load and instantaneous crack length are measured, then crack propagating velocities are calculated. Experiments on 40Cr steel show that the results given by this method have a good agreement with that obtained by the resistance fracture gage method. Therefore this method is feasible for measuring crack propagating velocities under high loading rate and will have wide application.     

采用热喷涂进行金属陶瓷复合材料的近净成形

现代技术的发展导致了具有特定机械性能的金属陶瓷复合材料的出现。但主要围难是高度复杂和昂贵的加工技术。热喷涂成形技术可能是解决该问题的途径．由于它的高度灵活性、低的造价和相对简单的等原因。用热喷涂技术进行复合材料的近净成形方法包括现场喷涂．压实和烧结体化的工艺。利用可移击型芯技术可产生不同的形状。当采用丝材或粉末形式的铝合金怍为基体材料时．两种粒子增强相(sic和AlO3)的漆加量可达50％的体积百分比。已实现了双枪喷涂技术(电弧-HVOF．电弧-火焰)和单枪喷漆技术(HVOI，火焰喷涂)。用这种技术加工的模型有锥体，喷嘴和内燃发动机排气孔的衬套等．这些部件正在接受鉴定。     

铝-空气电池中合金阳极的腐蚀性能研究

研制了含有少量Zn、Bi、Te、In、Gu、Pb和Ti之中单个元素或多种元素的铝合金,它们有可能用于碱性铝-空气电池中作为燃料来使用.合金化元素含量<1%的二元合金,在50℃的4MKOH溶液中显示出的腐蚀速率比纯铝在同样介质中的腐蚀速率要高.添加两种或更多种合金化元素时,在开路中的腐蚀速率急剧降低到比纯铝的还低很多.已确认一些含Ga、In、Ti和P的铝合金有希望作为高性能的燃料.已发现压力加工(冷加工)对腐蚀速率几乎没有可再现的影响,但是Al-O.5%Ga合金除外,这个合金在最小加工量为50%的冷加工后可显示出不同的腐蚀速率.腐蚀速率数据还表明,含很少量的合金化元素就足以能提高合金的抗腐蚀性能,而含量超过临界值后,几乎不改善合金的抗腐蚀性能.     

储砂斗中铸造用砂的流动

叙述了从储砂斗中放砂的困难。借助于垂直流动的现代砂斗激活装置(Modeern bin activator)有助于解决这类难题。     

CALCULATION OF TRANSFORMATION VOLUME FRACTION TO HQ590 HOT ROLLED STRIP STEEL DURING CONTINUOUS COOLING

On the basis of phase transformation kinetics, the transformation of γ→α,P,B have been investigated through considering the effect of deformation. The calculation methods of volume fraction have also been given. Comparing with common method, the simulated results are in more agreement with experiment results.     

NICKEL-BASED ALLOYS IN GE AIRCRAFT TURBINES：PAST,PRESENT ＆ FUTURE

1. Introduction Freedom to travel anywhere in the world, both quickly and inexpensively, defines our modern era. Despite year-to-year variation, the long term demand for travel by airplane continues to grow. Three ma- jor systems comprise the modern airplane: the aircraft structure that encompasses the fuselage, wings, and landing gear; the avionics that enable flight through crowded skies in nearly all weather conditions; and the propulsion system that powers the aircraft. Improvements in mat…     

STUDY ON THE TENSILE FATIGUE DAMAGE OF QUASI—ISOTROPIC COMPOSITE LAMINATES

Quasi-isotropic. laminates have isotropic elastic properties in all in-plane directions. Therefore, this kind of laminate is widely used for structural elements. The simplest stacking sequence of quasi-isotropic laminates is [0/-60/60]s. When the direction of applied axial load to [0/-60/60]s laminate is inclined at a 30-degree angle, we have the other quasi-isotropic laminate [30/-30/90]s under axial load. The failure mechanisms of these two laminates are, however, entirely different from each other because these two laminates have different distribution of the interlaminar stresses. It was confirmed by tensile fatigue tests that the [0/-60/60]s laminate does not show any visible fatigue damage, but the [30/-30/90]s laminate develops edge-delamination during cyclic loading. The analytical results were in good agreement with the experimental results.