Research on Behavior of Crater Wear of Hob in Dry Hobbing

众所周知，切削油用于高速钢（HSS）滚刀的滚齿加工。然而，最近，由于防止环境污染和操作人员的安全，以及降低切削油及其废物处理的成本，使用高速钢滚刀的无切削油滚切（干式滚切）已成为一个吸引人的中心。本文主要研究了不同类型的镀有TIN和（Al, Ti）N涂层的HSS滚刀材料在干滚加工过程中对表面的凹坑磨损行为。在铣床上用飞刀进行了实验。研究结果总结如下：(1)干式切削得到的凹坑磨损小于湿式切削（使用含硫脂肪油的液体），表明沉积的金属可能对凹坑磨损有影响。(2)切削速度在47 ~ 86 m/min范围内，随着切削速度的增加，涂层（Al, Ti）N的SKH 55和m 34滚刀材料的坑损磨损增大。当切削速度为117 m/min时，切削速率显著降低。(3)在所测试的所有滚刀材料中，滚坑磨损随螺纹数和滚刀进给量的增加而减小，即3螺纹滚刀和3.0 mm/rev滚刀进给量的条件有利于减小滚坑磨损。(4)采用全涂层刀具时，凹坑磨损机理是由于涂层薄膜的塑性变形导致其分层，基底出现后，与切削屑的磨蚀作用增加了凹坑磨损。(5)在所测试的滚刀材料中，相应的SKH55 + (Al, Ti)N涂层刀具适用于干式滚刀。

It is well known that cutting oils are used in hobbing with high-speed steel (HSS) hob. Recently, however, bobbing without cutting oils (dry hobbing) with HSS hob has become a center of attraction, because of prevention of environmental pollution and safety for the operator, as well as reduction of costs for cutting oil and its waste disposal. The behavior of crater wear on the face using different kinds of HSS hob materials coated with TIN and (Al, Ti)N in dry hobbing was mainly investigated in this research. Experiments were carried out using a fly tool on the milling machine. A summary of the research results is shown below : (1) The crater wear obtained with in dry cutting is smaller than that with in wet cutting (using a fluid containing sulfurized fatty oil), which was suggested that the deposited metal may affected on the crater wear. (2)From cutting speeds of 47 m/min to 86 m/min, the crater wear of corresponding to SKH 55 and M 34 hob materials coated with (Al, Ti)N increases with an increase in cutting speed. At a cutting speed of 117 m/min, it decreased remarkably. (3)With all of the hob materials tested, the crater wear decreases with increasing in number of threads and hob feed, that is, the condition of 3-thread hob and hob feed of 3.0 mm/rev is useful for decreasing it. (4)When using the fully coated tools, it was suggested that the crater wear mechanism is due to the plastic deformation of the coating film, which causes its delamination, after appearing the substrate, the crater wear increases by the abrasive action with the cutting chips. (5)Among the hob materials tested, the corresponding to SKH55 + (Al, Ti)N coated tool is suitable for dry hobbing.