Two laminated composites, 2024/3003 and 7075/6009 aluminum alloys were prepared by double-stream-pouring continuous casting (DSPCC) followed by plastic deformation and heat treatment. The interface characteristics bet...Two laminated composites, 2024/3003 and 7075/6009 aluminum alloys were prepared by double-stream-pouring continuous casting (DSPCC) followed by plastic deformation and heat treatment. The interface characteristics between the external and internal layers of the composites in the as-cast and plastic deformation conditions were analyzed. The results show that the macrostructure difference between the external and internal layers of both composite ingots in the as-cast condition can be clearly clarified but the gradient interfaces are not distinct. However, the macro-scale gradient layers can be demonstrated from the hardness distribution in the cross sections of the composite ingots. After plastic deformation, the gradient characteristic of the interface in the laminated composites maintains except for the decrease in the interface thickness. After plastic deformation and T6 heat treatment, the ultimate strength, yield strength and elongation of 2024/3003 composite plate are 2.35, 3.10 and 0.9 times of that of 3003 aluminum alloy, respectively. The ultimate strength and yield strength of 7075/6009 composite plate increase 47 % and 82 % of that of 6009 aluminum alloy, respectively and the elongation of the composite is still as high as 15.3 %.展开更多
Aluminum laminate is one kind of the rigidizable composite materials and plays an important role in construction of the inflatable space structure(ISS),which has potential application in space in the future.But the st...Aluminum laminate is one kind of the rigidizable composite materials and plays an important role in construction of the inflatable space structure(ISS),which has potential application in space in the future.But the study of the predecessors mainly focuses on the research of the mechanical behavior in the room temperature,for this reason,mechanical properties of the aluminum laminate in low-high temperature have been studied in this paper.The failure mechanism of the aluminum laminate is also analyzed in the microscopic view by JCXA-T33 electron probe.The results show uhat the temperature has significant influence on the strength and Young's modulus of the aluminum laminate.With the increase of temperature,both the strength and Young's modulus of the aluminum laminate decrease.A model between Young's modulus of the aluminum laminate and temperatures is obtained by using Arrhenius equation.The predicted values by the model agree well with the experiment values.展开更多
The objective of the present research was to determine the degree of masking which occurs when 0.2 mm densely sintered aluminum oxide is placed over substrates of various colors. 20 lighter and 20 darker substrates we...The objective of the present research was to determine the degree of masking which occurs when 0.2 mm densely sintered aluminum oxide is placed over substrates of various colors. 20 lighter and 20 darker substrates were made from a mixture of dental amalgam and resin in an aluminum mold. The thin (0.2 mm) disks of densely sintered aluminum oxide were placed on the various substrates. The color changes after masking by these disks were recorded using a Minolta Chroma Meter Ⅱ. The results showed that the color (L *, a *, b *) changes after placing the disks over the substrates were obvious and lead to statistical significant differences (P<0.000 1) in ΔE, ΔL *, Δa *, Δb *. The masking ability was more pronounced with the aluminum oxide over the dark substrates than the light substrates.展开更多
It is known that fiber metal laminates （FML） as one of hybrid materials with thin metal sheets and fiber/epoxy layers have the characteristics of the excellent damage tolerance, fatigue and impact properties with a ...It is known that fiber metal laminates （FML） as one of hybrid materials with thin metal sheets and fiber/epoxy layers have the characteristics of the excellent damage tolerance, fatigue and impact properties with a relatively low density. Therefore, the mechanical components using FML can contribute the enhanced safety level of the sound construction toward the whole body. In this study, the impact performance of carbon reinforced aluminum laminates （CARAL） is investigated by experiments and numerical simulations. Drop weight tests are carried out with the weight of 4.7 kg at the speed of 1 and 2 m/s, respectively. Dynamic non-linear transient analyses are also accomplished using a finite element analysis software, ABAQUS. The experiment results and numerical results are compared with impact load-time histories. Also, energy-time histories are applied to investigate the impact performance of CARAL.展开更多
Heterogeneous metals and alloys are a new class of materials with superior mechanical properties.In this paper,we engineered sandwich-structured pure aluminum laminates composed of middle coarse-grained layer and oute...Heterogeneous metals and alloys are a new class of materials with superior mechanical properties.In this paper,we engineered sandwich-structured pure aluminum laminates composed of middle coarse-grained layer and outer fine-grained layer via extrusion,rolling and annealing.By controlling the post-annealing regimes,a larger degree of microstructure heterogeneities such as boundary spacing,misorientation and texture across the hetero-interface were obtained,which resulted in obvious mechanical differences.Tensile tests indicated that the 300℃/30 min annealed laminates enabled a relatively high tensile ductility while simultaneously retaining a high strength,which was better than prediction by the rule-of-mixture.To explain the reasons behind it,the evolution of geometrically necessary dislocations and strain gradient at the hetero-interface zone were detected using in-situ tension and microscopic digital image correlation technique.It was found that with the increasing applied strain,a significant strain gradient was developed near the interface,which was accommodated by geometrically necessary dislocations,thereby contributing to higher hetero-deformation induced(HDI)strengthening and hardening.展开更多
基金Supported by Natural Science Foundation of China (Granted No 50575076, No 59905007)Guangdong Provincial Natural Science Foundation of China (Granted No 994250)Program for New Century Excellent Talents in University (Granted No NCET-07-0310)
文摘Two laminated composites, 2024/3003 and 7075/6009 aluminum alloys were prepared by double-stream-pouring continuous casting (DSPCC) followed by plastic deformation and heat treatment. The interface characteristics between the external and internal layers of the composites in the as-cast and plastic deformation conditions were analyzed. The results show that the macrostructure difference between the external and internal layers of both composite ingots in the as-cast condition can be clearly clarified but the gradient interfaces are not distinct. However, the macro-scale gradient layers can be demonstrated from the hardness distribution in the cross sections of the composite ingots. After plastic deformation, the gradient characteristic of the interface in the laminated composites maintains except for the decrease in the interface thickness. After plastic deformation and T6 heat treatment, the ultimate strength, yield strength and elongation of 2024/3003 composite plate are 2.35, 3.10 and 0.9 times of that of 3003 aluminum alloy, respectively. The ultimate strength and yield strength of 7075/6009 composite plate increase 47 % and 82 % of that of 6009 aluminum alloy, respectively and the elongation of the composite is still as high as 15.3 %.
文摘Aluminum laminate is one kind of the rigidizable composite materials and plays an important role in construction of the inflatable space structure(ISS),which has potential application in space in the future.But the study of the predecessors mainly focuses on the research of the mechanical behavior in the room temperature,for this reason,mechanical properties of the aluminum laminate in low-high temperature have been studied in this paper.The failure mechanism of the aluminum laminate is also analyzed in the microscopic view by JCXA-T33 electron probe.The results show uhat the temperature has significant influence on the strength and Young's modulus of the aluminum laminate.With the increase of temperature,both the strength and Young's modulus of the aluminum laminate decrease.A model between Young's modulus of the aluminum laminate and temperatures is obtained by using Arrhenius equation.The predicted values by the model agree well with the experiment values.
文摘The objective of the present research was to determine the degree of masking which occurs when 0.2 mm densely sintered aluminum oxide is placed over substrates of various colors. 20 lighter and 20 darker substrates were made from a mixture of dental amalgam and resin in an aluminum mold. The thin (0.2 mm) disks of densely sintered aluminum oxide were placed on the various substrates. The color changes after masking by these disks were recorded using a Minolta Chroma Meter Ⅱ. The results showed that the color (L *, a *, b *) changes after placing the disks over the substrates were obvious and lead to statistical significant differences (P<0.000 1) in ΔE, ΔL *, Δa *, Δb *. The masking ability was more pronounced with the aluminum oxide over the dark substrates than the light substrates.
基金supported by a grant-in-aid for the Na-tional Core Research Center Program from the Ministry of Education Science & Technology and the Korea Science & Engineering Foundation (No. R15-2006-022-01001-0)support by the Korea Science and Engineering Foundation (KOSEF) NRL Program grant funded by the Korea government (MEST) (No. R0A-2008-000-20017-0)
文摘It is known that fiber metal laminates （FML） as one of hybrid materials with thin metal sheets and fiber/epoxy layers have the characteristics of the excellent damage tolerance, fatigue and impact properties with a relatively low density. Therefore, the mechanical components using FML can contribute the enhanced safety level of the sound construction toward the whole body. In this study, the impact performance of carbon reinforced aluminum laminates （CARAL） is investigated by experiments and numerical simulations. Drop weight tests are carried out with the weight of 4.7 kg at the speed of 1 and 2 m/s, respectively. Dynamic non-linear transient analyses are also accomplished using a finite element analysis software, ABAQUS. The experiment results and numerical results are compared with impact load-time histories. Also, energy-time histories are applied to investigate the impact performance of CARAL.
基金supported by the National Natural Science Foundation of China(Nos.52071035 and U1764253)。
文摘Heterogeneous metals and alloys are a new class of materials with superior mechanical properties.In this paper,we engineered sandwich-structured pure aluminum laminates composed of middle coarse-grained layer and outer fine-grained layer via extrusion,rolling and annealing.By controlling the post-annealing regimes,a larger degree of microstructure heterogeneities such as boundary spacing,misorientation and texture across the hetero-interface were obtained,which resulted in obvious mechanical differences.Tensile tests indicated that the 300℃/30 min annealed laminates enabled a relatively high tensile ductility while simultaneously retaining a high strength,which was better than prediction by the rule-of-mixture.To explain the reasons behind it,the evolution of geometrically necessary dislocations and strain gradient at the hetero-interface zone were detected using in-situ tension and microscopic digital image correlation technique.It was found that with the increasing applied strain,a significant strain gradient was developed near the interface,which was accommodated by geometrically necessary dislocations,thereby contributing to higher hetero-deformation induced(HDI)strengthening and hardening.
