Abstract
It is well known that the machinability of D-type graphite iron cast in metal mould (to be shortened as D.I.C.M.) is superior to that of the other cast irons. But influence of chemical composition on the machinability has not been studied so far. Therefore, machinability of D.I.C.M. was studied by varying their chemical composition such as P, S and Ti.
The machining operation for estimating the tool-life was carried out on a lathe using a WC-Co sintered tool without coolant under the following conditions: depth of cut, 2.0mm; feed rate of the work piece, 0.4mm/rev; and speed of machining, 100 to 280m/min. The results are summarized as follows.
1) The machinability of D.I.C.M. is much superior to that of flake graphite cast iron or ductile cast iron with respect to the surface roughness and the ease of chip removal.
2) Sulfer in D.I.C.M. improves while phosphorus and titanium deteriorate the machinability. These phenomena were observed especially at a high cutting speed.
3) Within the range of the present experiment, the tool-life was inversely proportional to the cutting force. Therefore, the tool-life was accurately estimated by measuring the cutting force.
