Study Of Ancient Black Copper In Yunnan

that the black copper is the same as variegated copper and paktong are the i nvent i ons made by anc i ent Yunnan peop le,it has more than 200 years of history The paper studied the composition of black copper , microstructure and mechanical properties, coloring process and formula , the relations between colority and composition of black copper and its coloring mechanism It is demonstrated that the black copper was a kind of copper alloy with trace gold as additives;trace element was indispensable for the black copper;with proper silver additives we could decrease the gold content The black copper was a single phase alloy, its lattice structure was the same as copper when the b I ack copper was colored it was increased the resistant corrosion of salt, coloring formula of black copper content Cu+2 and Cl-1, the colority (black color) would change with increasing gold content From experiments and inferences we be lieved the coloring mechanism of black copper was that the Cu20 was formed at first and then this film of Cu20 was transformed into CuO at last through gold catalytic function...