1985 Volume 51 Issue 9 Pages 1705-1710
The generation mechanism of thermal cracks has been studied. High speed orthogonal intermittent cutting test was conducted. Acoustic emission signal detected during dry and wet cutting were compared with an aim to confirm the instant of thermal crack generation. Finite element method analysis was then employed to calculate the stress distribution inside the cutting tool in the cutting cycle. From the result of calculation a large peak of τmax which acts repeatedly on the latter part of tool-chip contact area during the cutting period is the cause of thermal cracks. In addition the use of soluble cutting fluid leads to the formation of tensile stress on the rake surface after the disengagement of tool, and thus accelerates the growth of thermal cracks.
