Tool surface design for optimum lubrication of tool and chip

实验研究了表面粗糙度、成形方法和刃口几何形状对刀具润滑性能的影响。结果表明：首先，采用酯基润滑剂时，前刀表面的各向同性粗糙度降低了刀具与切屑的摩擦，有利于润滑剂向界面的渗透；然而，如果使用矿物油，各向同性的粗糙度增加了刀具-切屑摩擦，因为吸附的润滑剂抑制了表面能低的氧化膜的形成。其次，短脉冲激光刃磨可以抑制刃口微切屑的产生，减少晶界缺陷和孔洞。此外，用脉冲激光磨削与TiN结合的PcBN时，cBN向hBN转变并形成TiB_2，可形成低摩擦的表面层。最后，发现存在稳定死金属行为刀边的平衡状态，以优化负陆宽度和角度。

Effects of surface roughness, shaping method and edge geometries on lubrication were experimentally investigated for optimum tool lubrication. Following result were obtained : Firstly, isotropic roughness on the rake face decreased tool-chipfriction to facilitate infiltration of lubricant into the interface if lubricantwith ester group was employed. However, if mineral oil was employed, the isotropic roughness increased the tool-chip friction as the adsorbed lubricant suppresses formation of oxide film with low surface energy. Secondly, tool sharpening with short pulse laser can suppress occurrence of micro chipping on tool edge to decrease defects of grain boundaries and voids. In addition, if PcBN bounded with TiN is sharpening by pulse laser grinding, a surface layer with low friction can be formed by transition from cBN to hBN and TiB_2 formation. Finally, it was found that equilibrium state to stabilize dead metal behaving tool edge exists tooptimize negative land width and angle.