抛光涂层硬质合金刀片加工钛合金的耐用度分析

目的提高涂层硬质合金刀具加工钛合金的切削性能及加工效率。方法采用化学机械抛光(Chemical Mechanical Polishing,CMP)对经过磨削加工的YG8硬质合金车削刀片前刀面进行抛光预处理,并使用CVD与PVD涂层工艺制备涂层。运用单因素试验法,对抛光涂层硬质合金刀片进行切削TC4钛合金的刀片耐用度试验,分析钛合金加工过程中刀具种类及切削参数变化对刀片耐用度的影响规律。采用扫描电子显微镜(SEM)和能谱仪(EDS)分析刀片的磨损机理。结果经过化学机械抛光处理后,硬质合金刀片的平均粗糙度由87 nm降低为19 nm,降低幅度达78.2%。相同切削参数时,抛光CVD硬质合金刀片的耐用度最大程度上比磨削CVD硬质合金刀片提高了75%,抛光PVD硬质合金刀片的耐用度最大程度上比磨削PVD硬质合金刀片提高了8.3%。可见采用化学机械抛光对硬质合金刀片进行加工是提高刀片表面平整度及耐用度的重要途径。结论抛光CVD硬质合金刀片的耐用度优于磨削CVD硬质合金刀片,抛光PVD硬质合金刀片的耐用度优于磨削PVD硬质合金刀片。

Durability Analysis of Polished and Coated Cemented Carbide Inserts in Cutting TC4 Titanium Alloy

The work aims to improve cutting performance and machining efficiency of coated cemented carbide tools in machining titanium alloy. Chemical mechanical polishing (CMP) was applied to polish and pre-treat rake face of cemented carbide YG8 turning insert which has been grinded, and coatings were prepared by adopting CVD and PVD coating processes. Insert durability test of cutting TC4 titanium alloy was performed to polished and coated cemented carbide inserts in single factor test method. Law of influence of tool category and cutting parameters variation on insert durability in the process of titanium alloy machining was analyzed. Wear mechanisms of the inserts were analyzed with scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). After the treatment of chemical mechanical polishing, average roughness of the cemented carbide inserts decreased by 78.2% from 87 nm to 19 nm. Given by same cutting parameters, durability of the polished CVD cemented carbide insert increased by 75% to a maximum extent than that of the grinding CVD cemented carbide insert, and the durability of polished PVD cemented carbide insert increased by 8.3% to a maximum extent than that of the grinding PVD cemented carbide insert. It could be concluded that applying chemical mechanical polishing to cemented carbide insert was an important way of improving surface smoothness and durability of insert. Durability of the polished CVD cemented carbide insert is superior to that of grinding CVD cemented carbide insert, and the durability of polished PVD cemented carbide insert is superior to that of grinding PVD cemented carbide insert.