纳米Cr2O3微粒对2024-T4微弧氧化膜结构及耐磨性能的影响

摘 要: 在含有不同浓度纳米Cr2O3微粒的硅酸盐体系电解液中对2024-T4铝合金进行微弧氧化处理,使用SEM观察陶瓷膜的表面形貌和截面形貌,使用EDS能谱仪分析膜层中各主要成分沿截面方向的分布,使用XRD分析陶瓷膜的相结构,使用纳米压痕硬度计测量陶瓷膜的硬度,使用粗糙度仪测量陶瓷膜的表面粗糙度,使用摩擦磨损试验机测量陶瓷膜的摩擦系数,使用激光共聚焦显微镜测量磨痕体积,评估磨损率,使用SEM观察磨痕形貌,结果表明：在电解液中加入纳米Cr2O3微粒后,制备的陶瓷膜中出现了Cr2O3相,电解液中纳米Cr2O3微粒浓度达到2.4g/L时,陶瓷膜的硬度最高,摩擦系数最小,磨损率最低,耐磨性最好。     

Study on the servo control system of MWEDM

MWEDMhas been applied widely in industry be-cause of its capability of machining any material with e-lectrical conductivity more than 0·01S/cm without con-tact, and achieving micro parts with high machiningprecision and low surface roughness[1,2]. HoweverMWEDM is a dynamic process; it demands a highspeed, quick response servo control system to keep theoptimum discharge gap between the work-piece andwire electrode, maintain stable gap discharge states toerode the work-piece, and keep the sp…     

Experimental study of MWEDM technology

This work deals with an experimental investigation of the machining characteristics of Micro Wire Electrical Discharge Machining (MWEDM). The MWEDM process consists of only one cutting operation yawing with machining conditions. Experimental results show that the peak current and pulse duration have an obvious influence on surface roughness and machining time, and they also have an optimum value for the highest cutting speed. The servo reference voltage influences the surface roughness and machining time as well. In particular,the surface characteristics of work-pieces and a micro wire electrode were analyzed in detail too. Utilizing a micro wire electrode with diameter 30μm, MWEDM can machine a micro slot 38μm wide, which proves that the discharge gap can be controlled not more than 4μm. It can also machine micro gears respectively with a module 40μm, thickness lmm, and a module 100μm, thickness 3.5mm. All kinds of micro shaped holes and complex micro parts can be easily machined as well.     

逆变式电火花加工脉冲电源的单片机控制方法

介绍了具人良好人机交互界面的逆变式电火花加工脉冲电源参数的键盘设定及显示、等电流脉宽加工脉冲的产生、加工电流峰值设定的单片机控制方法,并针对单片机系统极端恶劣的工作环境,阐述了抗干扰的软件和硬件措施。     

电火花加工技术的新发展

概括当今火花加工的新的成果及其发展方向,即电火花加工的高速度、高精度和自动化,介绍了电火花加工中的控制技术、机床本体脉冲电源和加工工艺等。