摘要
采用紫铜电极、Cu W70在变化的峰值电流(I)、脉冲宽度(ton)电参数下加工8418钢,研究电极材料及电参数对电火花加工表面质量的影响。测得了工件表面粗糙度、微观硬度、白层厚度、微裂纹,结果表明:采用紫铜电极加工时工件表面粗糙度(Ra)及白层厚度(WT)均比采用Cu W70时略大,但在精加工放电参数下,电极材料对表面粗糙度的影响区别并不明显。工件表面粗糙度与白层厚度随着峰值电流和脉宽的增大而增大,且峰值电流对白层厚度的增加起主要作用。显微硬度随着与工件表面距离的增大而急剧减小。在低放电能量时,两种电极加工的8418钢表面基本上没有微裂纹,质量较好;在中高放电能量时,紫铜电极加工的工件表面微裂纹的数量比Cu W70电极的要多,但裂纹宽度差别不大。
This study presents the influence of the electrode materials, electrical discharge parameters including discharge peak current and pulse time on the surface integrity of 8418 steel in EDM process. The surface roughness （Ra）, average white layer thickness （WT） and surface micro cracks of workpieee have been measured after EDM. The experimental results reveal that Ra and WT obtained with copper electrode is bigger than that with CuW70 electrode, but there is slight difference in Ra and WT in the finish process of EDM. The value of Ra and WT increase with the increasing of discharge current and pulse duration, the pulse current plays a major role on WT. There is no micro cracks on the workpiece surface under lower discharge energy and the better surface integrity is obtained. The number of micro cracks with discharge energy, the width of micro cracks copper electrode is more than that with CuW70 electrode under high are almost the same.
出处
《机械科学与技术》
CSCD
北大核心
2018年第1期76-80,共5页
Mechanical Science and Technology for Aerospace Engineering
基金
湖南省自然科学基金项目(2015JJ2026)
国家自然科学基金项目(51275165)资助
