Effect of binder-phase modification and Cr3C2 addition on properties of WC-IOC0 cemented carbide

For production of fine-grained and corrosion-resistant tungsten carbide (WC) based cemented carbides, addition of chromium carbide (Cr₃3C₂) in small amounts is standard practice. No systematic study, however, has been made of the effects of large additions (maximum 6 wt % ) of Cr₃C₂ as a substitute for tungsten carbide. This study focuses on the effect of hard-phase substitution by C₃C₂ in WC-1OCo cemented carbide. An attempt is also made to modify the binder metal cobalt by partial or complete substitution of nickel. Specimens were prepared using the standard liquid-phase sintering process and were tested for sintered porosity, mechanical properties, corrosion resistance, and microstructural parameters. Results confirm the findings of earlier workers regarding grain refinement and improvement of mechanical properties upon the addition of small amounts (<2 wt%) of Cr₃C₂. Modification of the binder phase improves indentation fracture toughness and corrosion resistance. Addition of Cr₃C₂ independent of the binder type improves corrosion resistance.     

堆焊用药芯焊丝生产过程中的质量控制

针对堆焊用药芯焊丝生产过程中的质量控制问题，从设备状态、合金粉末、包粉量、焊丝刚度、减径量、拔丝粉、拉拔力和拉拔速度等方面提出了相应的措施，以保证和提高药芯焊丝质量的稳定性。     

板料弯曲回弹的有限元模拟影响因素研究

阐述了板料成形数值模拟中回弹问题的研究历史和发展现状,分析了塑性弯曲加工中工件发生弯曲回弹的原因、特点及有限元模拟过程的影响因素,总结了回弹模拟的算法,从成形过程模拟和回弹计算两方面系统分析了影响回弹模拟准确性和收敛性的主要因素及改进方向,讨论了模具设计中回弹的补偿算法 ,并提出了当前控制回弹的基本方法     

铝—钢双金属复合轧制层厚比及轧制力的研究

用实验方法研究了铝－钢双金属复合轧制时层厚比的变化规律。给出了双金属复合时轧制力的计算式。     

中厚板轧机工作辊失效分析及对策

介绍了济钢中厚板厂使用国外高镍铬和高铬工作辊的主要失效形式 ,并对该工作辊的断裂和裂纹产生原因进行了分析 ,同时针对所存在的问题提出了对策和具体改进措施。     

BREAKAGE MECHANISM OF TUNGSTEN BASED ALLOY BLOCK FOR ELECTRO-HEAT UPSETTING

The breakage mechanism of W-Ni-Fe alloy in the process of electro-heat upsetting studied both theoretically and experimetnally, and also the behaviors of crack formation and propagation were analysed. Alloy suffers from corrosion and thermal-mechanical fatigue mutual function. Simultaneously, the practical ways to improve the anvil life was discussed.     

表面部分电极含金属芯压电纤维气流传感特性研究

含金属芯压电纤维可以模仿昆虫的毛发感受器,感知周围环境的气流变化。在含金属芯压电纤维的部分纵向表面涂镀电极,制备了表面部分电极含金属芯压电纤维传感器PMPF（Partial electrode of Metal core Piezoelectric Fiber）。基于平均电荷法,建立了悬臂梁结构PMPF准静态气流传感模型,分析了PMPF产生的电荷值与表面电极分布角度、纤维长度、气流流速和气流方向的关系。搭建了实验系统,测试了PMPF对冲击气流的响应,验证了理论模型。结果表明,PMPF的传感信号和气流流速成指数关系,和气流方向成“8”字形关系。PMPF具有气流速度和方向的传感性能。     

Effects of frequency dimming electronic ballast on a high‐pressure mercury thallium iodide discharge

This study focuses on the behavior of a cylindrical metal halide discharge lamp powered by frequency‐controlled electronic ballast. Half‐bridge electronic ballast was designed and achieved.     

城市轨道交通车辆段与维修基地的生产污水处理探析

简要分析了我国城市轨道交通车辆段与维修基地生产污水的特点,并对城市轨道交通车辆段与维修基地生产污水处理的有效措施进行了深入的探讨、分析,以供参考。     

电感传感器金属探测定位系统设计

本文以 LDC1000电感传感器以及飞思卡尔 Kinetis 系列微控制器 K60为核心,组成具有定位功能的金属探测系统。通过金属的涡流效应,对金属物体进行检测,能够在一定范围内迅速定位出金属物体的精确位置。经实验表明,距离物体中心定位误差不超过4 mm,最小可以检测出2 cm2大小的金属物体。测量数据在单片机中进行处理,软件上采用了数字滤波,进一步减少了误差干扰信号,提高了系统的稳定性与精确性。该系统可通过 LCD 液晶显示屏显示当前金属物体所在具体位置,并利用按键实现人机交互。