The fine fluidity in the process of
casting had a direct bearing on the surface effects of the cast. In
1993, in cooperation with No. 621 Research Institute of the
Ministry of Aerospace Industry, we made another test of the alloy
ingredients of the Yongle Bell, including the trace elements. We
obtained new data. For the first time we found that besides copper,
tin, lead, zinc, aluminum, iron and magnesium, the big bell
contained gold and silver. The gold was good for resisting rust and
corrosion, and the silver enhanced the fluidity of casting
fluid.