Abstract
Drilling and reaming tests were conducted to discuss the machinability in cutting resistance, working time, accuracy in the size of worked hole, etc. on modified high silicon aluminum cast alloy, called "Alusil."
The results showed that drilling resistance, in particular, thrust was extraordinarily high in Alusil, and the constant load required for drilling of Alusil was much greater as compared with that of general wrought aluminum alloys or no modified aluminum-silicon cast alloys. The drilling resistance was higher in heat-treated material than in as cast, and the resistance of the material in graphite mould was higher than that of the material in metallic mould. There was found a reciprocal relation between the torque and the drilling time under constant load and the above relation agreed with the results of the experiments in the past.
On the other hand, in reaming of Alusil, the thrust was rather small and the torque was very large. Also, in this case, the reaming resistance was higher in heat-treated material than in as cast, and the resistance of the material in graphite mould was higher than that of the material in metallic mould. The diameter of reamed hole was fairly larger than that of reamer, and the distortion in the size of the hole diameter was of ten recognized. However, the above distortion in heat-treated material was smaller than that in as cast material.
