Regardless of the design or materials of slitting knives, the manufacturer of slitting knives should provide the initial value of the cutting rate and the amount of feed for each tooth. In case of absence of these data, you should consult the technical department of manufacturer. The supplier should be familiar with the properties of their products in full-width slot milling, outer contour milling, plunge milling or slope milling, as most of the standard milling cutters can’t accomplish so many production process. For example, supposing that the milling cutter does not have a sufficiently large second tool orthogonal clearance, the slope of the slope milling will be reduced.
It is clear that it will incur the damage of slitting knives when the operation is beyond the processing capability of the slitting machine. The same is true for the milling, assuming that the cuttings cannot be discharged from the bottom of slot in a timely manner, the cuttings will be squeezed and the slitting machine will be damaged. In a word, these conditions are not favorable for the life of slitting knives when milling processing the high temperature alloy. Facts proved that it is also wrong to assume that slowing down the feed rate can extend the slitting life expectancy. The typical example you will find that the material is rather rigid with the first cutting.
Assuming that the feed quantity is reduced (for example, the amount of feed per tooth of indexable milling cutter is reduced to 0.025 ~ 0.5mm), the slitting blade will rub the work piece violently. As a result, the litting knives can be damaged quickly or immediately. Friction can lead to the process hardening of work piece surface. In order to avoid hardening, the cutting load (0.15 ~ 0.2mm/feed amount per tooth) should be maintained for the first cutting. The cutting depth depends on a variety of factors, such as the design of slitting knives, height of slitting knives, rigidity of fixture, tool length of tool, machine horsepower, etc. But it is the most suitable for processing the high-viscosity work piece when the cutting tool has a tool orthogonal rake and tool orthogonal clearance of 5 ° ~ 11 ° positive.