电弧离子镀和高功率脉冲磁控溅射AlTiN涂层及其切削性能研究

Preparation and Cutting Performance of AlTiN Coatings by Arc Ion Plating and High Power Pulsed Magnetron Sputtering

目的比较两种沉积方法制备的AlTiN涂层的切削性能。方法利用高功率脉冲磁控溅射技术(HiPIMS)和电弧离子镀技术(AIP),在硬质合金车刀片上沉积AlTiN涂层,比较和研究两种AlTiN涂层的组织形貌特性及综合性能。利用扫描电子显微镜和X射线能量色散谱仪,观察和检测涂层的生长形貌和元素含量。采用激光共聚焦扫描显微镜表征涂层的表面粗糙度。使用X射线衍射仪分析涂层的物相结构。使用纳米压痕仪测量涂层的纳米硬度以及弹性模量。通过干式车削试验研究涂层刀具的切削性能,并对其磨损机理进行分析。结果两种涂层均为柱状晶生长,HiPIMS制备的AlTiN涂层相较AIP制备的AlTiN涂层,具有更加光滑平整的表面。两者压痕硬度相近,约为30 GPa,但HiPIMS-AlTiN涂层的弹性模量更小。随着切削距离的不断增加,刀具后刀面磨损变得越来越严重,未涂层的车刀在切削1 min(180 m)时,磨损量超过200μm,达到了失效标准。在相同条件下切削9 min(1620 m),AIP-AlTiN和HiPIMS-AlTiN两种涂层刀具后刀面的磨损量分别为231μm和190μm,AIP-AlTiN涂层刀具已达到失效标准。结论干式车削316L不锈钢时,HiPIMS-AlTiN涂层刀具的切削寿命长于AIP-AlTiN涂层刀具,切削过程中,两种涂层刀具的主要磨损形式均为粘着磨损、磨粒磨损和氧化磨损。

AlTiN coatings were deposited by High Power Impulse Magnetron Sputtering(HiPIMS)and Arc Ion Plating(AIP)on cemented carbide and investigated concerning structure,mechanical properties,and turning performance.The scanning electron microscope with attached energy-dispersive X-ray spectroscopy was used to characterize growth morphology and coating composition.A laser confocal scanning microscope was employed to measure the surface roughness.X-ray diffractometer was utilized to analyze the phase structure of coatings,and coating hardness was detected by nanoindentation tests.Besides,the cutting performance and failure mechanism of coated turning inserts were studied by dry machining 316L stainless steel.Results reveal that the AIP-and HiPIMS-AlTiN coatings exhibit columnar grain growth,while the latter obtains a more smooth surface with lower surface roughness.The two coatings show a comparable hardness with a value of about 30 GPa.Whereas the HiPIMS-AlTiN has a lower elastic modulus,signifying a higher plastic deformation resistance.The flank wear length reaching to 200μm is the evaluation criteria of the tool wear.During the dry turning test,the uncoated insert is worn over 200μm after continuous cutting for 1 minute(cutting distance=180 m).However,when cutting for 9 min(1620 m),the flank wear lengths of AIP-AlTiN and HiPIMS-AlTiN coated tool was 231μm and 190μm,respectively,implying the HiPIMS coating had a superior cutting performance.The primary wear mechanisms of two coating tools are adhesion wear,abrasive wear,and oxidation wear.