IN718镍基高温合金电火花加工表面完整性初步研究

摘要

镍基合金具有优良的性能而获得广泛的应用,针对切削加工中存在的问题,采用与材料的力学性能无关的电火花进行加工,通过对其电火花加工实验,初步研究了峰值电流和脉冲宽度加工参数对加工表面完整性的影响规律。结果表明,表面粗糙度随峰值电流和脉冲宽度的增大而增大,与电极丝的运动方向无关。加工表面由微观组织规则的凹坑、熔滴和微小孔组成,加工表面无微观裂纹存在。显微硬度变化不大,无加工硬化现象。随脉冲能量减小,重铸现象减轻,加工表面完整性越好。%Nickel based super alloys are widely used in many areas because of its excellent performance.According to its turning problem,electrical discharge machining method is utilized in this paper to explore it machining surface intetrity.Experiments are carried out primarilly.The influence of pulse current and pulse on time on surface integrity is analyzed.Results show that surface roughness increases with the pulse current and pulse on time.The movement direction of has no effect on surface roughness.The SEM figures are characterized by discharge craters,droplets,micro-voids and debris.There is no micro cracks on the machined surface.The value of microhardness changes little.Low discharge energy results in small recast layer and good surface integrity.