Threading holes using tapping tools is a widely used machining operation in the industry. This manufacturing process involves a great tool immersion in the part, which involves both friction and cutting. This makes the use of coatings critical to improving tool life. Four coatings are used based on Physical vapor deposition (PVD) technology—TiN, TiCN, TiAlN and TiAlN+WC/C are compared to uncoated tool performance. The effect of various coatings on the life of M12 × 1.5 tapping tools during threading of through holes 20 mm deep, in GG25 casting plates, dry and applying cutting speed of 50 m/min. The end-of-life criterion has been established based on a cutting torque of 16 N-m. Taking the uncoated tap as a basis for comparison, it is observed that coatings based on PVD technologies increase tool life doubling in the most advantageous case with the TiAlN coating. PVD type coatings provide better protection to wear at cylindrical area of the tool, where the thread profile is finished, than uncoated taps. The teeth located in the cone-cylinder transition zone of the taps suffer the most wear regardless of the coating. However, taps coated with TiAlN+WC/C wear level values is lowest of all the coatings tested, which indicates a strong reinforcement in these teeth.

中文翻译：

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高速钢攻丝不同涂层的螺纹性能

使用攻丝工具的螺纹孔是工业上广泛使用的加工操作。该制造过程涉及将大量工具浸入零件中，这涉及摩擦和切削。这使得涂层的使用对于延长工具寿命至关重要。基于物理气相沉积（PVD）技术使用了四种涂层-将TiN，TiCN，TiAlN和TiAlN + WC / C与未涂层工具的性能进行了比较。在GG25铸板上的20毫米深的通孔穿入，干燥并以50 m / min的切削速度进行切削时，各种涂层对M12×1.5攻丝工具的寿命的影响。已根据16 Nm的切削扭矩建立了寿命终止标准。以未镀膜的水龙头作为比较的基础，可以看出，在最有利的情况下，使用TiAlN涂层时，基于PVD技术的涂层可使工具寿命延长一倍。与未涂覆的丝锥相比，PVD型涂层可更好地保护在螺纹轮廓已完成的工具圆柱区域的磨损。不论涂层如何，位于丝锥的圆锥圆柱过渡区中的齿都会遭受最大的磨损。但是，在所有测试的涂层中，涂有TiAlN + WC / C磨损等级值的丝锥最低，这表明这些牙齿具有很强的增强作用。