Relationships between microstructures and properties of chinese ancient bronzes
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.
Experiments on dissolving lead from bronze wares and the related questions
A series of experiments on dissolving lead from bronze wares indicate that the use of bronze wares containing lead in ancient daily life led to serious food pollution. Our ancestors had created the brilliant bronze civilization.However, the noble classes who were proud of the possession of the bronze wares also paid a great cost for using it, which brought a series of social problems.
The Occurrence of Metallic Iron in Ancient Copper
Abstract Of the many thousands of chemical or spectrochemical analyses of ancient copper, principally from central and northern Europe, and available in the literature, only a few report iron in excess of 1% and, in general, of these the iron occurs in Iron Age metal. On the other hand, some recent articles report much higher iron, these data being supplemented by our own investigations. These high-iron coppers are from Sardinia, Greece, Israel, Egypt, and India, and range in date from the Chalcolithic and Early Bronze Age through the Iron Age.Of 61 copper specimens found at Nichoria, a recently excavated site in the sw Peloponnese, 11 were found to be ferromagnetic, and ranged in age from Early Bronze Age to Byzantine. In a number of specimens, which have been examined spectrochemically and metallographically, the magnetic response is closely proportional to the total iron in the sample.Although Iron Age copper that contains appreciable iron can be explained by accidental addition of the impurity, no suc...