Aluminum and silver strips were cold welded by rolling and a bimetallic strip was produced. To create cold weld between A1 and Ag, mating surfaces were specially prepared and various rolling thickness reductions were ...Aluminum and silver strips were cold welded by rolling and a bimetallic strip was produced. To create cold weld between A1 and Ag, mating surfaces were specially prepared and various rolling thickness reductions were applied. The minimum critical thickness reduction to begin cold weld was specified as 70% which equals 0.1630 critical rolling shape factors. The bimetallic strips were treated by diffusion annealing at 400 ~C and various annealing time. The A1/Ag interface of strips was observed by scanning electron microscope to investigate the formation of hard and brittle probable phases. The effect of anneal time on diffusion distance and phase transformation was also analysed by EDS analysis and line scan. A diffusion region along the interface in the Ag side was observed and its width increased with prolonging annealing time. Some 8 phases were detected close to the interface after anneal treating for 3 h and 8 phase was thicker and more continuous by increasing annealing time. The microhardness measurement showed that in spite of formation of 8 phase due to diffusion annealing, the interface hardness was reduced.展开更多
The variations of microstructure and tensile behavior of an Al-Li-Cu-Mg-Zr alloy during aging are studied in this paper. It has been found that the fine δ-phase precipitated in the underaging condition and that the ...The variations of microstructure and tensile behavior of an Al-Li-Cu-Mg-Zr alloy during aging are studied in this paper. It has been found that the fine δ-phase precipitated in the underaging condition and that the δ-, S-and T1-phases precipitate in the peak aging and the overaging conditions. The alloy exhibits transgranular fracture on the underaging condition, and mixture of transgranular and intergranular ruptures in the peak aging and overaging conditions.展开更多
文摘Aluminum and silver strips were cold welded by rolling and a bimetallic strip was produced. To create cold weld between A1 and Ag, mating surfaces were specially prepared and various rolling thickness reductions were applied. The minimum critical thickness reduction to begin cold weld was specified as 70% which equals 0.1630 critical rolling shape factors. The bimetallic strips were treated by diffusion annealing at 400 ~C and various annealing time. The A1/Ag interface of strips was observed by scanning electron microscope to investigate the formation of hard and brittle probable phases. The effect of anneal time on diffusion distance and phase transformation was also analysed by EDS analysis and line scan. A diffusion region along the interface in the Ag side was observed and its width increased with prolonging annealing time. Some 8 phases were detected close to the interface after anneal treating for 3 h and 8 phase was thicker and more continuous by increasing annealing time. The microhardness measurement showed that in spite of formation of 8 phase due to diffusion annealing, the interface hardness was reduced.
文摘The variations of microstructure and tensile behavior of an Al-Li-Cu-Mg-Zr alloy during aging are studied in this paper. It has been found that the fine δ-phase precipitated in the underaging condition and that the δ-, S-and T1-phases precipitate in the peak aging and the overaging conditions. The alloy exhibits transgranular fracture on the underaging condition, and mixture of transgranular and intergranular ruptures in the peak aging and overaging conditions.
