Tool wear usually includes the following types: 1 flank wear; 2 Cut Wear; 3 Crescent Depression Wear; 4 blunt cutting edge; 5 chipped edge; 6 cracked cutting edge; 7 catastrophic failure.
There is no universally accepted uniform definition of tool life, which usually depends on different workpiece and tool materials, as well as different cutting processes. One way to Quantitative analysis tool life is to set an acceptable maximum flank wear limit (expressed in VB or VBMAX) . Tool life can be represented by the Taylor's Theorem of expected tool life, i.e. VCTN = c a more common form of the formula is VcTn dxfy = c where VC is the cutting speed, t is the tool life, d is the cutting depth, F is the feed rate; X and Y are experimentally determined; N and C are constants determined from experimental or published technical data and represent the properties of the tool material, workpiece, and feed rate.
The development of optimal tool matrix, coating and cutting edge preparation techniques is essential to limit tool wear and resist high cutting temperatures. These factors, together with the chip-breaking groove and corner arc radius used on the indexable inserts, determine the suitability of each tool for different workpieces and cutting operations. The optimum combination of all these factors can extend the tool life and make the cutting process more economical and reliable.