Abstract
Parts such as joints, valves, and water meter cases are typically made of lead bronze castings. Because of its harmful effects on the human body and the environment, use of lead is restricted for waterworks parts. The following are the results of research on the characteristics of thermal analysis curves, casting and solidification characteristics, and optimum cutting conditions of sulfide dispersed lead-free bronze castings newly developed by the authors.
(1) The spheroidal ratio sulfides of the alloy system used for the developed castings are related to the cooling speed of monotectic and eutectic reactions, which increases as the falling gradient of the cooling speed increases.
(2) Regarding the shrinkage cavities of Tatur's mold castings made of the same alloy system as that used for the castings developed this time CAC902 alloy, there are more internal shrinkage cavities but less external shrinkage cavities compared with the CAC902 alloy. This is due to the skin formation type solidification of the alloy system.
(3) Cutting tests were performed using an AC3000 ceramic tool on a lathe at 1,000rpm. Favorable results were observed in the range of effective rake angles from 5 to 8 degrees.
