【摘要】 切削过程中金属层流过剪切区发生塑性变形后形成切屑。抛光的板状纯铁作被加工材料,通过刨屑快速退刀获得的切屑,用光学显微镜及扫描电子显微镜观察切屑层片内的表面滑移带。滑移带的数量、形状和分布,可反映金属塑性变形的程度和方向,并可间接地推测位错均行为。滑移带间距为1—3μm,带与带之间基本上无塑性变形。层片宽度为30—50μm,比滑移带间距大一个数量级,各层片内有数量不等的滑移带。研究结果说明在一般切削条件下,(a_p=0.3,O.7mm),切屑形成由层片间发生相互变形和层片内晶面发生滑移引起的。更多还原

【Abstract】 During metal cutting, the metal plastic deformation occurred on shearing plane zone. Chip was obtained by guick stop of cutting toom from planer material of polished commercial pure iron. The surface of its lamella was observed under optical microscope and scanning electronic microscope (SEM). There are many slip lines on the surface. The number, shape and distrabution of slip lines indicate the degree and direction of plastic deformation during metal cutting and infers the behaviour of dislocation. There is a 1～3μm gap of no plastic deformation between the slip bands. The lamella is 30～50μm in width, a distance ten times larger than those between slip bands. In general machining condition (a_p=0.3,0.7mm), the deformation of chip results from deformation on neighbouring lamellas and from shear slip on crystal face within a lamella.更多还原