X-ray diffaction analysis(XRDA)data of the black or brown patina on the surfaces of eight kinds of bronze mirror samples show 4 or 5 broad diffuse peaks which corresponding to almost the same 20 angle, while their mat...X-ray diffaction analysis(XRDA)data of the black or brown patina on the surfaces of eight kinds of bronze mirror samples show 4 or 5 broad diffuse peaks which corresponding to almost the same 20 angle, while their matixes does not.These results indicate that those diffuse peaks were produced by the SnO2, microcrystals of 3 ￣5 nm size contained in the black or brown patina.The matrix of unearthed black patina bronze mirror numbered 223, gives strong XRDA diffraction peaks, indicating that there are a large amounts of non-oxidized bronze alloy particles surrounded by SnO2,which shows that the black patinas are not wholly metallic oxides (mainly SnO2),there are also a lot of original alloys of different sizes in grain in the patina.The bright-field image of the black patina sample gives the same result.展开更多
The typical morphology of alloy lead（Pb） in ancient bronzes made in the Spring-Autumn Warring States Period（770 B.C.-221 B.C.）,China,was examined by using electron microscopic techniques.We propose that the main p...The typical morphology of alloy lead（Pb） in ancient bronzes made in the Spring-Autumn Warring States Period（770 B.C.-221 B.C.）,China,was examined by using electron microscopic techniques.We propose that the main purposes for adding metallic Pb in a large quantity into ancient bronzes,such as arrows and ritual vessel-Ding,were for increasing weight and economical reasons.In order to promote adding efficiency and improve casting quality for getting homogenously distributed Pb particles in the bronzes,a process through inserting Pb rod into the mold is supposed to be used during casting,which provided a process for preventing Pb sinkage.Scanning electron microscope（SEM） observations from the fracture surface of the bronzes revealed that the Pb particle possessed a ＂hollow-cored bubble＂ structure,which was formed due to absorbing casting gases during solidification and therefore indirectly eliminated the casting porosity and loosen.展开更多
The formation of the black patina induced by soil humic asid under different conditions was studied, theblack, grey and brown colored shiny surfaces prepared in laboratory were analyzed. As a result the formation ofti...The formation of the black patina induced by soil humic asid under different conditions was studied, theblack, grey and brown colored shiny surfaces prepared in laboratory were analyzed. As a result the formation oftin-rich shiny black surface on bronze mirrors is the product of soil corrosion of the bronze mirrors. The patina isformed by reection between the alloy and the humic acid in soil, and leaching of copper and lead oxides through along period time when the mirrors were buried under the ground leaving a dense compact corrosion-resistant layerconsisted predominantly of stannic oxide microcrystal.展开更多
文摘X-ray diffaction analysis(XRDA)data of the black or brown patina on the surfaces of eight kinds of bronze mirror samples show 4 or 5 broad diffuse peaks which corresponding to almost the same 20 angle, while their matixes does not.These results indicate that those diffuse peaks were produced by the SnO2, microcrystals of 3 ￣5 nm size contained in the black or brown patina.The matrix of unearthed black patina bronze mirror numbered 223, gives strong XRDA diffraction peaks, indicating that there are a large amounts of non-oxidized bronze alloy particles surrounded by SnO2,which shows that the black patinas are not wholly metallic oxides (mainly SnO2),there are also a lot of original alloys of different sizes in grain in the patina.The bright-field image of the black patina sample gives the same result.
基金Supported by the National Natural Science Foundation of China(J1210061)
文摘The typical morphology of alloy lead（Pb） in ancient bronzes made in the Spring-Autumn Warring States Period（770 B.C.-221 B.C.）,China,was examined by using electron microscopic techniques.We propose that the main purposes for adding metallic Pb in a large quantity into ancient bronzes,such as arrows and ritual vessel-Ding,were for increasing weight and economical reasons.In order to promote adding efficiency and improve casting quality for getting homogenously distributed Pb particles in the bronzes,a process through inserting Pb rod into the mold is supposed to be used during casting,which provided a process for preventing Pb sinkage.Scanning electron microscope（SEM） observations from the fracture surface of the bronzes revealed that the Pb particle possessed a ＂hollow-cored bubble＂ structure,which was formed due to absorbing casting gases during solidification and therefore indirectly eliminated the casting porosity and loosen.
文摘The formation of the black patina induced by soil humic asid under different conditions was studied, theblack, grey and brown colored shiny surfaces prepared in laboratory were analyzed. As a result the formation oftin-rich shiny black surface on bronze mirrors is the product of soil corrosion of the bronze mirrors. The patina isformed by reection between the alloy and the humic acid in soil, and leaching of copper and lead oxides through along period time when the mirrors were buried under the ground leaving a dense compact corrosion-resistant layerconsisted predominantly of stannic oxide microcrystal.
