Width Of Flank Wear Land Research Articles

切削過程の動特性に及ぼす工具摩耗の影響

In order to study the mechanics of machining chatter, an investigation into the dynamics of metal cutting process has been carried out using experimental approaches. In this paper, turning experiments are carried out to evaluate the effect of tool wear on the dynamic stiffness of metal cutting process, employing the tool attached to a cantilever-type structure which is excited sinusoidally in the direction of its principal mode. The experimental results are shown to agree with the theoretical model including the effect of the dynamic force which acts on the flank wear land. The results obtained are as follows. (1) When the tool vibrates in the normal direction to the cut surface, the damping effect is induced which depends on the width of flank wear land and the wave length of chatter marks. (2) When the worn tool vibrates in the parallel direction to the cut surface, the negative damping effect is induced if the frequency of the tool vibration is over 1 000 Hz.

A short-time method for the assessment of the machinability of low carbon free machining steels

The machinability of 14 casts of low carbon free machining steel has been measured by an extensive study of the wear of M2 High Speed Steel tools, based on the International Standards Organisation (I.S.O.) testing procedure. A consideration of the characteristic wear curves of these tools shows that flank wear land width prior to catastrophic failure of the tool decreases with increase in cutting speed or flank wear rate. The proposed short-time test is based on the observed tool wear and tool life characteristics. Essentially the test involves the measurement of a portion of the secondary steady wear stage of an M2 cutting tool which can be extrapolated either numerically or graphically to give the time of catastrophic failure of the tool. The test allows tool life to be predicted to better than ± 10 per cent for this class of workpiece machined with M2 High Speed Steel tools.

Constriction-resistance concept applied to wear measurement of metal-cutting tools

The paper describes a mathematical model for the tool-workpiece-interface resistance in a single-point oblique-cutting operation on a lathe. The model is developed using the concept of constriction resistance, and is verified by practical measurements of the interface resistance. The measurement technique is important, and details are given of the significant factors. It is shown that the resistance measurements may be used to calculate the amount of wear on the cutting tool as cutting proceeds. Results show that this method gives the mean value of the flank wear-land width to within ±0.002 in (±0.05 mm) of independent optical measurements for a range of cutting conditions typical of finish-turning operations.