Why PCD tools are not suitable for rough processing？

Polycrystalline diamond (PCD) tools for processing aluminum workpieces have the advantages of long tool life and high metal removal rate. But the disadvantages is expensive and high processing cost. When processing various newly developed aluminum alloy materials (especially high-silicon-content composite materials), in order to optimize productivity and processing quality, the grade and geometric parameters of PCD tools must be carefully selected to meet different processing requirements. Its applicability is restricted by different workpiece material.

When processing aluminum alloy materials, the work life of carbide tools is only about 5% than PCD tools, the rough cutting speed of carbide tools is about 120m/min. PCD cutting speed can reach 360m/min.

Tool manufacturers recommend using fine-grained (or medium-grained) PCD for silicon-free and low-silicon aluminum alloy materials, and rough-grained PCD for high-silicon aluminum alloy.

The correct application of PCD tool is the premise to obtain good working result. in order to reduce the cutting force and prevent the formation of debris, PCD tools should use positive cutting Angle. However, when processing high silicon aluminum alloy (especially when PCD tool is used to replace the carbide tool for processing), the rear Angle of PCD tool is better than the original carbide tool used to slightly reduce the rear Angle (such as 25°), in order to improve the cutting performance of PCD tool edge on high silicon aluminum alloy. The positive rake angle of a PCD tool should not be too large, because the larger the tool rake angle, the lower the cutting edge strength. In other words, the smaller the rake angle of the PCD tool, the higher the cutting edge strength.