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1.
型砂水分红外光谱在线检测方法的探讨   总被引:1,自引:0,他引:1  
在讨论了各种型砂水分检测方法的基础上,提出了型砂水分光谱检测方法,介绍了这种方法的基本原理,设计了检测仪器,并对这种方法用于型砂水分在线检测进行了初步探讨。  相似文献   

2.
作者提出了一种新造型方法,这种造型方法利用电磁冲击力来紧实型砂。此方法紧实型砂速度快,其速度高于目前已有的造型方法;并且能量消耗小,造型机构简单,易于同现有技术和工装配合,作者研究了用这种造型方法做成铸型的紧实度分布规律,分析了相应的影响因素。  相似文献   

3.
TLP连接技术研究进展   总被引:10,自引:1,他引:9  
TLP连接方法是一种常用于难焊金属,尤其是复合材料和导种材料的重要连接方法,自上世纪50年以来,在Ni基,Co基耐热合金,Ti合金,半导体材料,复合材料,复合材料以及异种材料的连接中得到了大量的应用,70年代以来,众多的研究者对TLP连接机理进行了大量的研究工作,取得了很大的成就,重点从TLP连接方法的发展入手,比较系统地总结了研究TLP连接过程动力学的各种方法,研究结果为TLP连接方法的研究和应用提供了重要的理论基础。  相似文献   

4.
二次调节液压系统的开关-模糊-PID控制   总被引:3,自引:0,他引:3  
对二次调节控制系统,提出了一种基于模糊控制的复合控制方法,此方法利用了模糊控制的优点,又保留了传统PID控制的长处。经实时运行,表明该控制方法精度高,动态性好。  相似文献   

5.
碳载纳米钯催化剂半工业级制备工艺研究   总被引:2,自引:4,他引:2  
对浸渍方法,活性碳载体,还原方法进行了筛选试验。结果表明:浸渍方法决定Pd/C催化剂中钯粒子粒度的大小,在载体上的分布均匀性及催化活性;还原方法是决定催化活性大小的又一决定性因素,活性碳载体的性质也影响催化剂的性能,根据试验结果,选择了较佳的浸渍方法S-6,C-8活性碳,还原方法R-4,建立了半工业级的生产工艺,用此工艺可生产出钯粒度3-10nm,催化活性等于或优于日本同类产品的催化剂。  相似文献   

6.
张龙  熊国良  李嶷 《机床与液压》2005,(3):192-193,173
针对所研究的机床故障诊断专家系统,以故障树分析法为基础,采用面向对象的事件知识表示方法。并以面向对象编程技术给出了知识表示的示例。分析了这种知识表示方法的特点。实践证明,这种知识表示方法在故障诊断专家系统中是确实有效的,而且这种表示方法融合了多种传统知识表示方法的长处,是一种值得研究与应用的方法。  相似文献   

7.
作者在数字积分插补方法的基础上,发展一种多坐标的完全软件插补方法-多维直线插补方法。该方法具有精度高,适用性强和易于实现等特点,可望得到广泛应用,本文对该方法的基本原理及实现方法进行了简单的介绍,并给出了应用实例。  相似文献   

8.
过程诊断层次分析法及其应用   总被引:1,自引:1,他引:0  
根据过程管理理论的要求,提出了综合因果图分析和失效模式影响分析方法的一种过程诊断方法——过程诊断层次分析法,研究探讨了这种方法的具体实施步骤和方法,开展了案例研究,实践证明该方法是一种有效的具有易操作性,兼顾定性和定量分析的优点的过程诊断方法。  相似文献   

9.
建立了铸件充型过程的数学模型,探讨了充型过程常用的计算方法SOLA-VOF方法。采用SO-LA方法求解速度场和压力场,并利用改进的VOF方法处理三维自由表面,包括自由表面的确定、自由表面的移动.进行了充填过程的模拟计算,验证了所采用的计算方法的可靠性。  相似文献   

10.
基于VRML的虚拟模型的构建和交互   总被引:3,自引:0,他引:3  
介绍了VRML建模的常规方法,比较了现行建模方法的特点,总结了基于语义的描述建模方法,详述了模型开发过程中的建模、转换、装饰、动画和交互等关键技术,最后通过实例展示了运动车床的虚拟模型。  相似文献   

11.
Suspension and solution thermal spray coatings   总被引:3,自引:0,他引:3  
The emerging methods of coating deposition by suspension and solution thermal spraying are described. The liquid suspensions of fine powders and liquid precursors are injected into flames and/or jets generated in the torches. The formulation and stability of suspensions as well as the methods of fine powders synthesis are briefly described. Typical solutions, being often the liquid organo-metallics are also briefly described. An important problem of injection of liquids into jets and flames is then presented. Two principal modes of injection, used at present, are outlined, i.e.: (i) atomization; and, (ii) injection of a continuous jet. Subsequently, the phenomena occurring in flames and plasma jets are discussed and the major differences to these occurring during conventional spraying are stressed up. The build up of coatings starting from the impact of fine particles on the substrate is described and typical microstructures of suspension and solution sprayed coatings are shown. Some properties of the sprayed coatings, including mechanical, electrical, chemical, and thermophysical ones are collected and presented. Finally, the emerging applications of coatings are shown and the possible future applications are discussed.  相似文献   

12.
Modular fixtures are distinguished for their high flexibility. Previous researches focused on 2-D objects or 3-D objects with regular geometry. This paper introduces our systematic study of 3-D modular fixtures, particularly for complex objects. For the sake of both function and simplicity, three baseplates are arranged equilaterally. One baseplate is fixed horizontally, on which three fixels are installed to support the object. The other baseplates are moveable and at least one fixel is set on either of them. Totally, seven fixels are adopted. Efficient algorithms are presented for computing optimal fixel locations for the given object pose regarding localization accuracy and immobilization capability. On account of the manufacturing errors, measuring and adjusting techniques are developed to improve the localization accuracy. Case studies are investigated to illustrate applications. Experiments are performed for verifying the principles, including the well-known theoretical proposition that seven fixels are necessary and sufficient for fixturing a 3-D object of nonrevolutionary surface.  相似文献   

13.
镁合金抗氧化及合金化阻燃研究进展   总被引:5,自引:0,他引:5  
综述了镁合金氧化燃烧及燃点的测定方法、镁合金抗氧化和阻燃机理及合金元素(Ca,Be,RE,Y)对镁合金阻燃性能影响的研究现状。介绍了抗氧化和阻燃镁合金研制进展及应用现状,指出了研究中存在的问题及发展方向。  相似文献   

14.
通过建立具有代表性的平板类气体辅助注射成型产品模型,借助注塑成型CAE软件Moldflow对该模型进行了一系列分析模拟。通过对模拟结果数据的综合分析和数学处理,得到了气体注射参数对气道穿透长度的影响规律、气体注射参数设置及气道穿透长度预测公式。  相似文献   

15.
张俊  周波 《模具制造》2006,6(11):24-26
介绍了熔体片冲孔模结构及主要零件的设计,设计了符合冲压工艺的多品种模具结构,分析了模具关键零件的设计和制造,并考虑了模具的镶拼结构及模具中使用反推杆结构,保证了细小凸模的刚度不受影响,提高了整副模具的使用寿命,同时设计了送进和取出熔体片的工位器具,获得了满意的使用效果。  相似文献   

16.
The tensile rupture locations of friction stir welded joints of AA2017-T351 and AA6061-T6 aluminum alloys were examined. The experiments show that the rupture locations of the joints are different for the two aluminum alloys, which are influenced by the welding parameters. When the joints are free of welding defects, the AA2017-T351 joints are ruptured in the weld nugget adjacent to the thermo-mechanically affected zone on the advancing side and the rupture surfaces appear as oval contours of the weld nugget, while the AA6061-T6 joints are ruptured in the heat affected zone on the retreating side and the rupture surfaces are inclined at a certain degree to the bottom surfaces of the joints. When welding defects are present in the joints, the AA2017-T351 joints are ruptured in the weld center, while the AA6061-T6 joints are ruptured on the retreating side near the weld center. The rupture locations of the joints are dependent on the internal structures of the joints and can be explained through them.  相似文献   

17.
钢结硬质合金材料的研究进展   总被引:5,自引:0,他引:5  
介绍了钢结硬质合金的性能特点及制备工艺,简述了近年来在钢结硬质合金领域开展的研究与取得的进展,对钢结硬质合金的应用进行了分类归纳,展望了其发展前景。  相似文献   

18.
超声电镀锡铋合金研究   总被引:5,自引:0,他引:5  
研究了超声波对锡铋合金电镀的影响.通过赫尔槽试验优选出最佳镀液配方和工艺条件,用SEM法观测了镀层形貌,并测试了镀层和镀液性能.结果表明:超声波的作用扩大了电流密度范围和温度范围;所得镀层表面光亮、结晶更细致、均匀,镀层结合力、抗氧化性和可焊性改善明显,耐蚀性增强;镀液性能稳定,阴极电流效率和沉积速度得到提高.因此,超声波对电镀工艺条件、镀层质量和镀液性能都有明显的改善作用.  相似文献   

19.
电弧传感器的研究现状与展望   总被引:7,自引:0,他引:7  
贾剑平  张华  徐健宁 《焊接》2005,(11):14-18
电弧传感器作为一种实时传感的器件,与其它类传感器相比,具有结构简单、成本低以及跟踪灵敏度高等特点,焊接时不需要附加设备.详细综述了电弧传感器的分类、焊接工艺性能、电弧传感器的数学模型以及电弧传感器技术的研究及应用状况,并对今后的电弧传感器的发展前景作了展望.  相似文献   

20.
So-called oxide dispersion strengthened steels or nanostructured ferritic alloys (NFAs) contain nanoprecipitates which give them exceptional mechanical properties and resistance to radiation effects. However, the structure and composition of these nanoprecipitates are still uncertain. To help clarify the nature of the smallest nanoprecipitates, density functional theory calculations are used to investigate the most stable Ti, Y, and O nanocluster computational units in Fe. Two distinct methods for searching for stable nanoclusters are proposed: one in which nanoclusters are restricted to the body-centered cubic Fe lattice and one in which the nanocluster structures are strained variants of bulk Ti and Y oxides. We discovered that nanoclusters that are structurally similar to bulk Ti and Y oxides are significantly more stable than nanoclusters that are restricted to the Fe lattice. Consequently, the most stable nanoprecipitates in Ti-Y-O NFAs are more likely to be small oxide phases than coherent solute-enriched clusters.  相似文献   

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