Analysis of bell materials:Tin bronzes

The present study was set up to examine the effect of alloying elements （including harmful elements） on metallurgical features （material properties and qualitative parameters） of tin bronzes, with particular reference to church bells from Middle Ages to Current times. A driving force of this study was to identify and demonstrate features related to the quality of church bells made in different centuries. The findings have been derived via metallographic and chemical analysis of specimens of bells from various parts of Australasia and Europe. The bell materials consisted of a mixture of the a phase and the （α＋β） eutectoid essentially, in proportions determined by tin content and mould materials during casting. The samples from the 15th century to the one from the 20th century showed a progressive increase in hardness, ranging from the minimum of -280 VHM20g to a maximum of -470 VHM20g for the （α＋β） eutectoid, and -160 VHM20g to -230 VHM20g for the a phase. The investigation also shows that the sound decay of the bell decreased with lowering the wt.% of tin and increasing the wt.% of lead and silver. This information is expected to provide an additional interesting knowledge into manufacturing practices and their significance in the quality of church bells over past centuries.

Diffusion bonding of titanium alloy to tin-bronze

The vacuum diffusion bonding of titanium alloy to tin bronze has been studied and the feasibility and appropriate processing parameters have been investigated. The maximum tensile strength of the joints is 168 MPa , and a firm joint is obtained. The microstructure of diffusion bonded joint has been observed by SEM, X ray and EPMA, and the main factors affecting diffusion bonding have been analyzed. The intermetallic compounds Ti 2Cu and TiCu were formed near the interface. The width and quantity of the intermetallic compound increases with the increase of the bonding time. The formation of the intermetallic compounds results in embrittlement of the joint and the poor joint properties.

The welding technique in building the largest bronze Buddha in the world

The Temple-of-heaven Buddha,situated on the Mo Yu Peak of Da Yu Hill in Hong Kong,is the largest open air bronze statue of Buddha in the world.The key technique of the Buddha developing project is the welding pro- cess.This paper states the adoption of combination of MIG and TIG process with special filler wires in the Buddha project,and the satisfactory results achieved.

Processing limit maps for the stable deformation of dieless drawing

Tin bronze wires were produced by dieless drawing. The effects of heating power, the distance between cooler and heater as well as feeding speed on the diameter, the temperature field, and the deformation region profile of the wires were investigated. The results indi-cated that each processing parameter exhibited both lower and upper limits of stable deformation based on the criterion of stable deformation with the diameter fluctuation of ±0.05 mm. Both the temperature and its gradient of the deformation region increased with increasing heating power under stable deformation, but decreased with an increase in feeding speed. As the distance between cooler and heater increased, the temperature of the deformation region increased and the slope of the deformation region profile decreased. The processing limit map of sta-ble deformation exhibited a closed curve and the unstable deformation consisted of wire breakage and diameter fluctuations.