Effect of Cu on Microstructures of Manganese Steel by EDXA and SEM

In order to investigate the distribution of Cu and Mg, and the effect of Cu on the microstructure of steels, manganese steels containing various Cu contents were annealed at 1260, 1100 and 1000℃, respectively, for I h and subsequently cooled to room temperature in the furnace to simulate the pre-rolling anneal. The results indicate that Cu is not microscopically segregated in the annealed steels. The scanning electron microscopy （SEM） observation shows that the main microstructure consist of ferrite and pearlite; the percentage of pearlite in the steels increases with increasing Cu content. The grain size reduces with the decrease of the annealing temperature. The results of energy dispersive X-ray analysis （EDXA） suggest that Cu content in pearlite is higher than that in ferrite, demonstrating that the microstructure-segregation of Cu occurred. However, the cast specimens show that Cu content in MnS and S-rich phases is high. In addition, Cu of 0.2%-0.4% could improve the distribution of MnS and S-rich inclusions. The optimal Cu content in steels and the optimal annealing temperature between 1100-1200℃ were determined.

Hot mold casting process of ancient East India and Bangladesh

Ancient casting process for production of brass or bronze utensils and icons were made in hot molds using clay molded investment casting or piece mold process,as presumed by archaeologists.Piece mold process is still traditionally practiced in many parts of Eastern India and Bangladesh along with investment casting process.Incidentally,Bengal artisans are more accustomed to piece mold process unlike tribal artisans who practiced investment casting process.This piece mold casting process has been reconstructed to get the idea of metal characteristics in order to investigate ancient casting process of Bengal and Bangladesh.The characterization of ancient archaeo-metal products come to a type of cast Cu-Sn-Zn-Pb type quaternary alloy produced by a slow freezing process.Though these alloys physically differ from the traditional cast alloy of binary Cu-Zn type brass,the physical characteristics are similar to the binary cast alloy character.This investigation throws light on the similarity of the production processes by which ancient artisans probably produced cast metal products.

Promoting osteointegration effect of Cu-alloyed titanium in ovariectomized rats

Osteoporosis is a common skeletal disease making patients be prone to the osteoporotic fracture.However,the clinical implants made of titanium and its alloys with a poor osseointegration need a long time for healing and easily to loosening.Thus,a new class of Cu-alloyed titanium(TiCu)alloys with excellent mechanical properties and bio-functionalization has been developed.In this study,the osteoporosis modeled rats were used to study the osteointegration effect and underlying mechanism of TiCu.The results showed that after implantation for 4 weeks,TiCu alloy could promote the reconstruction of vascular network around the implant by up-regulating vascular endothelial growth factor expression.After 8weeks,it could further promote the proliferation and differentiation of osteoblasts,mineralization and deposition of collagens,and then significantly increasing bone mineral density around the implant.In conclusion,TiCu alloy would enhance the fixation stability,accelerate the osteointegration,and thus reduce the risk of aseptic loosening during the long-term implantation in the osteoporosis environment.This study was the first to report the role and mechanism of a Cu-alloyed metal in promoting osteointegration in osteoporosis environment,which provides a new attractive support for the improvement of future clinical applications of Cu-alloyed antibacterial titanium alloys.