Research About Microstructure and Wear Resistance of Hardfacing Layer on Cast Iron

It's simple technology to manufacture big trimming die by hardfacing on the base metal of cast iron. The chemical composition, microstructure, hardness, wear resistance and wear mechanism of the hardfacing layer were studied.The experimental results indicate that the hardfacing technology has much more advantages and cheaper than that of traditional process. The chemical composition, microstructure, hardness of the hardfacing metal are all satisfied for manufacturing the big trimming die by welding on cast iron. The wear resistant test of hardfacing layers were carried out by using two different electrodes. The wear resistance of new electrode hardfacing layer is higher than that of normal hardfacing electrode D322. The wear mechanism of hardfacing layer is belongs to abrasive wear model.     

Corrosion Resistance of an electrodeposited Zinc Coating Containing CeO2 Nanoparticles

A Zinc coating containing CeO2 nanoparticles has been deposited by electrodeposition in a zinc plating bath.The content of CeO2 in the coating is 0.22 mass%. The results of weight loss experiments and electrochemistry tests show that corrosion resistance of the Zinc coating containing CeO2 nanoparticles is remarkably improved in contrast to the pure zinc coating in 0.5 M MgSO4 solution. The effects of CeO2 microparticles on the corrosion resistance of the zinc coating have been studied, the results show that CeO2 microparticles have no effect on the corrosion resistance of the zinc coating. SEM and XRD experiments suggest that the presence of CeO2 nanoparticles in the coating causes the modification of the surface morphology and preferential orientation of the crystal planes; therefore, the reason for the enhancement of corrosion resistance is mainly related to improvement of the structure of the coating.     

含钢骨架橡胶密封条的冲切加工

含钢骨架橡胶密封条的冲切加工不同于单独的橡胶或金属材料的加工。文中给出了适合的刀具参数和夹具设计，这些刀具和夹具被应用在某型家用汽车密封条生产线，使用情况良好。     

基于图的夹具特征识别方法研究

夹具特征识别是实现夹具自动化设计的基础。本文在属性邻接图的基础上,给出了一种通过几何推理实现夹具特征识别的方法。在该方法中定义了制造特征方向,并通过最大凹边凝聚的方法,实现了极限表面的识别,在此基础上通过一系列几何推理算法来识别夹具特征。该方法可以有效地解决CAD与夹具设计CAD之间的集成问题,为自动化夹具设计探索了一种新的途径。     

一种混合集成电路共晶焊接用石墨夹具的设计

在某贯军标混合集成电路产品研制过程中,陶瓷基片共晶焊接的焊透率直接影响产品的噪声系数、增益等重要特性指标。文中设计了多组均匀分布、独立配重的倒扣式一体化石墨组件,可实现共晶焊接载体限位。倒置时多组重针悬空,不施压;正置时多组重针自动下垂,对基片等均匀配重施压,最终完成一致性共晶焊接。采用该设计方法研制的石墨夹具能有效解决基片等偏移和空洞率高的问题,保证了电路单元的接地性能,突破了该贯军标混合集成电路产品的批量研制技术瓶颈,提高了批量成品的质量一致性水平。焊透率检测及重要指标测试结果验证了该方法的可行性和有效性。     

卧轴回转式镗削缸体柱塞孔夹具

介绍镗削 10CY14 1B型高压油泵缸体七个柱塞孔车床夹具。分析其结构型式和工作原理 ,此夹具适合中小型企业的批量生产。     

孔系组合夹具系统中装夹稳定性的校验

当用CAD软件系统设计组合夹具时,通过对夹紧力和定位支承反作用力之间的平衡作出评估,即可判定系统的定位可靠性.     

弯道零件的斜孔加工

对于零件弯道的两个3空间斜孔,原通过组合夹具定位后,采用划线加工,加工质量不能满足图纸要求。针对该问题,指出了划线加工的不足,并采用新的加工方法,即在立卧转换加工中心上,开发并运用其潜在的"循环19(即零点跟踪)"功能,从而显著提高了整机的性能。     

工件夹具的可行夹紧区域确定方法

提出一种根据形封闭原理确定工件可行夹紧区域的方法。该方法针对预先确定定位配置的情况,依据形封闭原理计算出可以使工件达到形封闭的可行夹紧区域,夹具布局设计人员可以在该区域内选取所需的夹紧位置。该方法可以有效地处理工件的夹紧表面为凹面的情况。     

变速箱上盖拔叉孔加工夹具设计

变速箱上盖是汽车用来换档的重要零部件之一,它可以改变传动比,满足不同行驶条件对牵引力的需要。就变速箱上盖拔叉孔加工夹具设计方案进行论述,通过采用这套夹具体和钻模,不但保证了工件的形位要求,提高了该产品的加工质量,同时也缩短了辅助加工时间,提高了生产效率。