Abstract
The dendrite arm spacing, one of variable of cast structure, or cooling rate during solidification was applied as a criterion for machinability of various Al-Cu, Al-Si and Al-Mg casting alloys in turning tests. Refining the dendrite arm spacing leads to reduction in tool wear in accordance to the empirical equation VB = kDn, where D is dendrite arm spacing, VB flank wear of the tool, and k and n constants. Roughness of finished surfaces is remarkably increased with decreasing the cooling rate during solidification as a result of coarsening of secondary constituents. Decreasing the cooling rate remarkably increases the number of chips. The cutting force is independent of the cooling rate.
