高速切削刀具磨损表面形态研究

Wear Characteristics of Cutting Tools in High Speed Machining

对立方氮化硼刀具、陶瓷刀具、涂层刀具及超细晶粒硬质合金刀具高速铣削灰铸铁、调质45#钢和淬硬45#钢时的刀具磨损形态及其磨损机理进行观察和分析.结果表明:在高速切削条件下,不同刀具材料与工件材料匹配时的刀具磨损形态主要表现为前刀面磨损、后刀面磨损、微崩刃、剥落和破损等;高速切削时刀具的前刀面磨损形态不同于常速切削时的磨损形态,即磨损不表现为月牙洼的形式,而是表现为切削刃处磨损最大的斜面磨损形式,前刀面磨损区域随切削速度提高而减小,但磨损深度增大.研究结果可用于指导高速切削刀具材料的设计、合理选用及刀具磨损控制.

The wear characteristics of PCBN tool, ceramic tool, coated carbide tool and ultra fine grain carbide tool in high speed face milling of cast iron, AISI-1045 tempered carbon steel, and AISI-1045 hardened carbon steel were examined with a tool-making microscope. The results showed that the cutting tools had different wear modes when the material pair of the cutting tool and workpiece changed. The dominant wear patterns of the cutting tools included rake face wear, flank wear, micro-chipping, fracture and breakage. The rake face wear of the cutting tools in high speed machining was different from that in conventional speed machining. Namely, the rake face was not characterized by crater wear but by slope-plane-wear with the maximum wear at the cutting edge, while the worn area of the rake face decreased with the increase of cutting speed and the wear depth increased correspondingly. The results might be helpful to guiding the design and selection of tool materials and the control of tool wear in high-speed machining process.