分形理论在放电修整超硬磨料砂轮实验中的应用研究  

The Application of Fractal Theory in Electrical Discharge Truing /Dressing Diamond Grinding Wheels

作　　者：蔡兰蓉[1] 阮文裕[1] 胡德金[2] 李敏[1] 

机构地区：[1]天津职业技术师范大学高速切削与精密加工重点实验室,天津300222 [2]上海交通大学机械与动力工程学院,上海200030

出　　处：《兵工学报》2013年第7期853-857,共5页Acta Armamentarii

基　　金：国家自然科学基金项目(50775143);天津市自然科学基金项目(10JCYBJC07000);天津职业技术师范大学科研启动项目(KYQD08010)

摘　　要：电火花放电修整(EDD)砂轮技术利用放电产生的热能熔融气化结合剂使磨粒突出修锐砂轮,是很有发展前途的特种加工修整方法。放电加工的介质放电轨迹显示出树枝分叉倾向,具有明显的分形结构,其形态是影响放电能量分布的重要因素。基于分形理论对煤油、空气及雾状去离子水3种放电介质的热能量分布特征进行分析,并在3种介质中进行青铜结合剂金刚石砂轮EDD实验。研究结果表明:基于分形几何学的仿真放电轨迹特征与金刚石砂轮实验修锐质量基本符合,可以利用介质的放电图形及分形维数来预测砂轮的修锐微观形貌及修锐质量。Electrical discharge dressing （EDD） process is a non-traditional promising truing and dressing technology for superabrasive wheels. The process makes use of electrical energy to melt and vaporize the wheel bond, and make the abrasive grains stick from the grinding wheel. The development of lightning leader displays a stochastic discharge channel with branching and tortuous structure during EDD. It obvi- ously has characteristic of self-similarity, which can be well described by fractals. A discharge channels simulation model based on the fractal theory shows the thermal energy distribution of various discharge mediums on the diamond wheel. And various discharge mediums including kerosene-based oil, impressed air and misted deionized water, are applied on EDD bronze-bonded diamond grinding wheels. The sur- face topography of dressed diamond grinding wheel is observed by VHX-1000 three-dimensional digital microscope. The analyses indicate that the surface topography of dressed diamond grinding wheel is con- sistent with the feature of simulation discharge channel based on the fractal theory. At the same time, the fractal simulation model of discharge channels is benefit to predict the wheel dressing microstructure and fressing quality.

关 键 词：机械制造工艺与设备 分形理论 放电介质 修锐 金刚石砂轮 

分 类 号：TG580.61[金属学及工艺—金属切削加工及机床]