Unearthing technology's influence on the ancient Chinese dynasties through metallurgical investigations

Bronzes from ancient civilizations provide insight into the cultures of 4000 years ago. There is great appreciation for the progression of metallurgical processing techniques that evolved over thousands of years. The materials and metallurgical techniques can be studied to provide information about material structure and the technology used to manufacture the objects. Investigations of structure and chemistry are useful for documentation as well as for preservation and restoration, establishing better estimates about timelines, place of origin and probable use. Several of the artifacts in the Tseng collection were examined in the Advanced Materials Laboratory at California State University Northridge (College of Engineering). Most of the samples were too large to directly place in the chamber of a Scanning Electron Microscope, so analysis was done on surface deposits removed with carbon tape. The Chinese objects included a bronze vessel with jade dragon handles and a copper/gold lid, a bronze guang with animal characteristics, and a bronze ding. For each sample, micrographs were taken, spectrum analyses were obtained and elemental compositions were calculated. Actual bronze alloy percentages vary significantly in the amounts of copper (90% - 50%), tin (10% - 50%), lead, silver and iron used for ancient bronzes. Many of the artifacts demonstrate thin walled casting and unique surface decoration. The ancient Chinese developed a most unusual casting method called the piece mold process where surface decoration could be made by carving into the mold or into the model. The Tseng collection provides possibility for metallurgical examination and collaboration with archaeologists and conservators from other institutions on a cultural and scientific level, giving an unprecedented opportunity to explore the art, material culture and spiritual life of ancient China.