1997 Volume 47 Issue 2 Pages 78-83
In turning of hyper-eutectic Al–Si system casting alloy, it is desirable to add Cu less than about 0.5% and as little Mg as possible in that alloy for the tool wear, because the tool wear remarkably increases by adding Cu or Mg to that alloy. While, in that alloy (JIS AC9A or AC9B) containing both of Cu and Mg each 0.5~1.5%, the refinement of primary silicon in that alloy by casting to a metallic mold having larger cooling rate during solidification than a sand mold, and use of cutting oil in turning of that alloy are very effective in decreasing the tool wear. The finished surface roughness of that alloy is effectively improved and the size of chip becomes remarkably fine by adding Cu or Mg.
