The evaluation of machinability of GGG 90 ductile iron in terms of cutting forces surface roughness and tool wear

Spheroidal graphite cast iron is widely used in the automotive industry due to good mechanic properties and GGG 90 grade spheroidal graphite cast iron is preferred for crank shafts and connecting rods.In this study, machinability of GGG 90 grade spheroidal graphite cast iron connecting rod has been investigated according to ISO 3685 in terms of cutting forces, surface roughnes and tool wear. Machinability tests were performed at four different cutting speeds (250, 300, 350 and 400 m/dak), three different feed rates (0,2, 0,25 and 0,3 mm/rev) and 1,6 mm depth of cut by turning without coolant. In the tests, K10/20 grade cementide carbide without coating, K10/20 grade coated (TiN- ? "Al" ? _"2" "O" _"3" -MT/TiCN) with CVD method cementide carbide, K05/10 grade coated (TiN-TiCN-TiN) with PVD method cermet and K10/20 grade coated (TiN- ? "Al" ? _"2" "O" _"3" ) with CVD method ceramic tools were used for recommended spheroidal graphite cast iron.After cutting tests, cutting tools have been compared. Best surface roughness has been obtained by uncoated carbide tool but surface roughness has been quickly increased due to more tool wear. The lowest cutting forces have been measured in the experiments by coated carbide tool. Cermet tool has been showed the best performance in the wear experiments