加工工艺对机械零件表面完整性的影响

Influence of machining process on surface integrity of the mechanical components

研究了多步制孔快进给、多步制孔慢进给和一步复合制孔3种加工工艺对高强度材料7075铝合金板材紧固孔表面完整性的影响.结果表明:1)多步制孔快进给和慢进给工艺的表面粗糙度相近,而多步制孔慢进给和一步复合制孔工艺的表面微观形貌、表层硬化程度、残余应力分布状况等质量评价指标均优于多步制孔快进给工艺;2)一步复合制孔工艺加工表面粗糙度最小,加工硬化程度最小,应力分布稳定,几乎没有变质层,是一种高效、快捷、零件加工表面完整性好的加工工艺.鉴于此,评价零件表面加工质量,仅以表面粗糙度为指标是不全面的,应根据表面完整性的全部技术指标来综合评价.

The influence was investigated of the three drilling processes in multiplestep machining with fast and slow feeding and onestep compound process on surface integrity of fastening holes drilled on high strength material 7075 aluminum alloy plateThe results show that machined surface roughness of the former two machining process are approximate,the surface quality in microphotograph,work hardening,residual stress distribution generated in multiplestep machining with slow feeding and onestep compound process are superior to drilling process with fast feedingOnestep compound process is an effective,quick machining way with high surface integrity because it has the smallest roughness,work hardening,steady residual stress distribution and very thin surface metamorphosis layers.Therefore,it is not perfect that roughness is regarded as only estimating machined quality standard.Surface quality of the mechanical components should be evaluated comprehensively with the respect of surface integrity.