Showing papers on "Built up edge published in 1988"

Effect of soft additives (Pb, Bi) on formation of built-up edge

Abstract: The effect of soft additives (Pb, Bi) on the formation of built-up edge (BUE) and the effect of BUE on several aspects of machinability have been investigated in AISI 1200 series low carbon resulphurised free machining steels. The size of BUE was found to decrease with increasing Pb or Bi content, with Bi being more effective in reducing the size. It has been confirmed that the presence of BUE reduces the cutting force and protects tools from wear. It has been inferred that soft additives control tool wear mostly indirectly by affecting the form and stability of BUE, cutting force, and temperature. From observations made on large broken BUE segments on the chips, it is suggested that soft additives provide sites for easy shear and microfracture through the effect of liquid metal embrittlement. The observed reduction of BUE size with increasing soft additive content could be explained by this mechanism. Based on these observations, it is suggested that non-uniform microstructural distribution in th...

Estimation of turning finish roughness on the presence of built-up edge.

Abstract: In terms of measuring the fall-off fragments of the built-up edges on the finished surface during orthogonal cutting, it is shown to be capable of estimating the turning surface roughness. The distributions of the over cuts by the built-up edges on the orthogonal cutting consist with the Weibull distribution, and provide information on the mechanism of the formation process of the finished surface during three dimensional cutting. The actual depth of cut is varied by the position at the turning tool edge, therefore, the results indicate that maximum height (Rmax) of surface roughnesses on the turning are assessed from integration of over cuts on the orthogonal cutting.