Residual Stress in Disc Milling Grooving of Titanium Alloy

In the present study, the formation mechanism and distribution rule of residual stress in disc milling grooving of titanium alloy were studied. The residual stress was measured by x ray diffraction method. First, a polybasic linear regression model about residual stress was established by linear regression technology, which was tested by "F" method. Then, the effect of milling parameters ( spindle speed, depth of cut and feed speed) on residual stress was investigated. The results showed that sigma(Ax) and sigma(Ay) (sigma(Ax) and sigma(Ay) represented the residual stress of machined surface made by the tool main cutting edge in x and y directions, respectively) increased with the increase of depth of cut and feed speed, but decreased with the increased spindle speed. For sigma(Bx) (sigma(Bx) represented the residual stress of machined surface made by the tool minor cutting edge in x direction), the residual stress decreased with the increase of spindle speed and depth of cut, but increased with the increase of feed speed. The effect of feed speed on sigma(Ax) and sigma(Ay) was most obvious, then was spindle speed. sigma(Bx) was most sensitive to depth of cut, then was feed speed, the last was spindle speed. Residual compressive stress was observed on all machined surface and subsurface. In addition, the residual stress on A surface and subsurface was bigger than B surface and subsurface, it was due to the combination effect of milling force and milling heat.