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 RPS method,which integrates the real numerical solution, the perturbation solution and the shooting solution reasonably,can obtain the complex solution of a slab waveguide with small gain/loss regions without sear...The RPS method,which integrates the real numerical solution, the perturbation solution and the shooting solution reasonably,can obtain the complex solution of a slab waveguide with small gain/loss regions without searching the root in the entire complex plan.A revision to the RPS method is presented so that it can deal with the waveguide including large gain/loss regions.The application indicated that the simulation results are precise.展开更多
GLARE （glass fibre/epoxy reinforced aluminum laminate） is a member of the fiber metal laminate （FML） family, and is built up of alternating metal and fiber layers. About 500 m2 GLARE is employed in each Airbus A38...GLARE （glass fibre/epoxy reinforced aluminum laminate） is a member of the fiber metal laminate （FML） family, and is built up of alternating metal and fiber layers. About 500 m2 GLARE is employed in each Airbus A380 because of the superior mechanical properties over the monolithic Muminum alloys, such as weight reduction, improved damage tolerance and higher ultimate tensile strength. Many tons of new GLARE scraps have been accumulated during the Airbus A380 manufacturing. Moreover, with the increasing plane orders of Airbus A380, more and more end-of-life （EOL） GLARE scrap will be generated after retire of planes within forty years. Thermal processing is a potential method for the material recycling and re-use from GLARE with the aim of environmental protection and economic benefits. The current study indicatdes that thermal delamination is a crucial pre-treatment step for the GLARE recycling. The decomposition behavior of the epoxy resins at elevated temperatures was investigated by using the simultaneous thermal analysis, thermogravimetry analysis （TGA） and differential scanning calorimetry （DSC）. Based on the thermal analysis results, GLARE thermal delamination experiments at refined temperatures were carried out to optimize the treatment temperature and holding time.展开更多
This paper presents an approach for recognizing both isolated and intersecting geometric features of freeform surface models of parts,for the purpose of automating the process planning of sheet metal forming.The devel...This paper presents an approach for recognizing both isolated and intersecting geometric features of freeform surface models of parts,for the purpose of automating the process planning of sheet metal forming.The developed methodology has three major steps:subdivision of B-spline surfaces,detection of protrusions and depressions,and recognition of geometric features for sheet metal forming domain.The input geometry data format of the part is based on an IGES CAD surface model represented in the form of trimmed B-spline surfaces.Each surface is classified or subdivided into different curvature regions with the aid of curvature property surfaces obtained by using symbolic computation of B-spline surfaces.Those regions satisfying a particular geometry and topology relation are recognized as protrusion and depression(DP) shapes.The DP shapes are then classified into different geometric features using a rule-based approach.A verified feasibility study of the developed method is also presented.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 RPS method,which integrates the real numerical solution, the perturbation solution and the shooting solution reasonably,can obtain the complex solution of a slab waveguide with small gain/loss regions without searching the root in the entire complex plan.A revision to the RPS method is presented so that it can deal with the waveguide including large gain/loss regions.The application indicated that the simulation results are precise.
基金the Royal Netherlands Academy of Science and Arts(KNAW)(No.10CDP026)the National Outstanding Young Scientist Foundation of China (No.50825401)the National Natural Science Foundation of China(No.50821003)
文摘GLARE （glass fibre/epoxy reinforced aluminum laminate） is a member of the fiber metal laminate （FML） family, and is built up of alternating metal and fiber layers. About 500 m2 GLARE is employed in each Airbus A380 because of the superior mechanical properties over the monolithic Muminum alloys, such as weight reduction, improved damage tolerance and higher ultimate tensile strength. Many tons of new GLARE scraps have been accumulated during the Airbus A380 manufacturing. Moreover, with the increasing plane orders of Airbus A380, more and more end-of-life （EOL） GLARE scrap will be generated after retire of planes within forty years. Thermal processing is a potential method for the material recycling and re-use from GLARE with the aim of environmental protection and economic benefits. The current study indicatdes that thermal delamination is a crucial pre-treatment step for the GLARE recycling. The decomposition behavior of the epoxy resins at elevated temperatures was investigated by using the simultaneous thermal analysis, thermogravimetry analysis （TGA） and differential scanning calorimetry （DSC）. Based on the thermal analysis results, GLARE thermal delamination experiments at refined temperatures were carried out to optimize the treatment temperature and holding time.
文摘This paper presents an approach for recognizing both isolated and intersecting geometric features of freeform surface models of parts,for the purpose of automating the process planning of sheet metal forming.The developed methodology has three major steps:subdivision of B-spline surfaces,detection of protrusions and depressions,and recognition of geometric features for sheet metal forming domain.The input geometry data format of the part is based on an IGES CAD surface model represented in the form of trimmed B-spline surfaces.Each surface is classified or subdivided into different curvature regions with the aid of curvature property surfaces obtained by using symbolic computation of B-spline surfaces.Those regions satisfying a particular geometry and topology relation are recognized as protrusion and depression(DP) shapes.The DP shapes are then classified into different geometric features using a rule-based approach.A verified feasibility study of the developed method is also presented.
