The influence of technical parameters on the infiltrating height of the moltenmetal in the process of Producing aluminium alloy foam by low-pressure infiltration method were investigated.Experiments indicated that the...The influence of technical parameters on the infiltrating height of the moltenmetal in the process of Producing aluminium alloy foam by low-pressure infiltration method were investigated.Experiments indicated that the height increases with the preheating temperature of granules,theexternal pressureand the pouring temperature of molten alloy,among which the action of pre heating temperature of granules is more effective.There exists a critical pre heating temperature for different size of granules.展开更多
The fatigue analyses of AlSi7 closed-cell aluminium foam were performed using a real porous model and three different homogenised material models:crushable foam model,isotropic hardening model and kinematic hardening ...The fatigue analyses of AlSi7 closed-cell aluminium foam were performed using a real porous model and three different homogenised material models:crushable foam model,isotropic hardening model and kinematic hardening model.The numerical analysis using all three homogenised material models is based on the available experimental results previously determined from fatigue tests under oscillating tensile loading with the stress ratio R=0.1.The obtained computational results have shown that both isotropic and kinematic hardening models are suitable to analyse the fatigue behaviour of closed-cell aluminium foam.Besides,the kinematic hardening material model has demonstrated significantly shorter simulation time if compared to the isotropic hardening material model.On the other hand,the crushable foam model is recognized as an inappropriate approach for the fatigue analyses under tension loading conditions.展开更多
To effectively reuse high-titanium blast furnace slag （TS）, foam glass-ceramics were successfully prepared by powder sintering at 1000℃. TS and waste glass were used as the main raw materials, aluminium nitride （...To effectively reuse high-titanium blast furnace slag （TS）, foam glass-ceramics were successfully prepared by powder sintering at 1000℃. TS and waste glass were used as the main raw materials, aluminium nitride （AIN） as the foaming agent, and borax as the fluxing agent. The influence of the amount of A1N added （lwt%-5wt%） on the crystalline phases, microstructure, and properties of the produced foam glass-ceramics was studied. The results showed that the main crystal phases were perovskite, diopside, and augite. With increasing A1N content, a transformation from diopside to augite occurred and the crystallinity of the pyroxene phases slightly decreased. Initially, the aver- age pore size and porosity of the foam glass-ceramics increased and subsequently decreased; similarly, their bulk density and compressive strength decreased and subsequently increased. The optimal properties were obtained when the foam glass-ceramics were prepared by adding 4wt% AIN.展开更多
Terrorist attacks using improvised explosive devices （IED） can result in unreinforced masonry （URM） wall collapse. Protecting URM wall from IED attack is very complicated. An effective solution to mitigate blast e...Terrorist attacks using improvised explosive devices （IED） can result in unreinforced masonry （URM） wall collapse. Protecting URM wall from IED attack is very complicated. An effective solution to mitigate blast effects on URM wall is to retrofit URM wails with metallic foam sheets to absorb blast energy. However, mitigation of blast effects on metallic foam protected URM walls is currently in their infancy in the world. In this paper, numerical models are used to simulate the per- formance of aluminum foam protected URM walls subjected to blast loads. A distinctive model, in which mortar and brick units of masonry are discritized individually, is used to model the perform- ance of masonry and the contact between the masonry and steel face-sheet of aluminum foam is modelled using the interface element model. The aluminum foam is modelled by a nonlinear elas- toplastic material model. The material models for masonry, aluminum foam and interface are then coded into a finite element program LS-DYNA3D to perform the numerical calculations of response and damage of aluminum foam protected URM walls under airblast loads. Discussion is made on the effectiveness of the aluminum foam protected system for URM wall against blast loads.展开更多
采用粉末冶金发泡法制备了Fe Al Fe、Ti Al Ti泡沫铝芯三明治结构 ,研究了泡沫铝芯的膨胀规律 ,分析了面板与泡沫铝芯的冶金结合过程 ,提出了微观结合机制。试验发现 ,结合界面由扩散反应形成的金属间化合物以及冷却得到的凝固组织两部...采用粉末冶金发泡法制备了Fe Al Fe、Ti Al Ti泡沫铝芯三明治结构 ,研究了泡沫铝芯的膨胀规律 ,分析了面板与泡沫铝芯的冶金结合过程 ,提出了微观结合机制。试验发现 ,结合界面由扩散反应形成的金属间化合物以及冷却得到的凝固组织两部分组成 ,从而形成良好的冶金结合。展开更多
文摘The influence of technical parameters on the infiltrating height of the moltenmetal in the process of Producing aluminium alloy foam by low-pressure infiltration method were investigated.Experiments indicated that the height increases with the preheating temperature of granules,theexternal pressureand the pouring temperature of molten alloy,among which the action of pre heating temperature of granules is more effective.There exists a critical pre heating temperature for different size of granules.
基金The authors would like to thank the Ministry of Education,Science,and Sport of the Republic of Slovenia for financial support(Research Core Funding No.P2-0063).
文摘The fatigue analyses of AlSi7 closed-cell aluminium foam were performed using a real porous model and three different homogenised material models:crushable foam model,isotropic hardening model and kinematic hardening model.The numerical analysis using all three homogenised material models is based on the available experimental results previously determined from fatigue tests under oscillating tensile loading with the stress ratio R=0.1.The obtained computational results have shown that both isotropic and kinematic hardening models are suitable to analyse the fatigue behaviour of closed-cell aluminium foam.Besides,the kinematic hardening material model has demonstrated significantly shorter simulation time if compared to the isotropic hardening material model.On the other hand,the crushable foam model is recognized as an inappropriate approach for the fatigue analyses under tension loading conditions.
基金the Science and Technology Support Projects of Sichuan Province (No. 2014GZ0011)the Industry Promotion Projects of Panzhihua in China (No.2013CY-C-2) for their financial support
文摘To effectively reuse high-titanium blast furnace slag （TS）, foam glass-ceramics were successfully prepared by powder sintering at 1000℃. TS and waste glass were used as the main raw materials, aluminium nitride （AIN） as the foaming agent, and borax as the fluxing agent. The influence of the amount of A1N added （lwt%-5wt%） on the crystalline phases, microstructure, and properties of the produced foam glass-ceramics was studied. The results showed that the main crystal phases were perovskite, diopside, and augite. With increasing A1N content, a transformation from diopside to augite occurred and the crystallinity of the pyroxene phases slightly decreased. Initially, the aver- age pore size and porosity of the foam glass-ceramics increased and subsequently decreased; similarly, their bulk density and compressive strength decreased and subsequently increased. The optimal properties were obtained when the foam glass-ceramics were prepared by adding 4wt% AIN.
文摘Terrorist attacks using improvised explosive devices （IED） can result in unreinforced masonry （URM） wall collapse. Protecting URM wall from IED attack is very complicated. An effective solution to mitigate blast effects on URM wall is to retrofit URM wails with metallic foam sheets to absorb blast energy. However, mitigation of blast effects on metallic foam protected URM walls is currently in their infancy in the world. In this paper, numerical models are used to simulate the per- formance of aluminum foam protected URM walls subjected to blast loads. A distinctive model, in which mortar and brick units of masonry are discritized individually, is used to model the perform- ance of masonry and the contact between the masonry and steel face-sheet of aluminum foam is modelled using the interface element model. The aluminum foam is modelled by a nonlinear elas- toplastic material model. The material models for masonry, aluminum foam and interface are then coded into a finite element program LS-DYNA3D to perform the numerical calculations of response and damage of aluminum foam protected URM walls under airblast loads. Discussion is made on the effectiveness of the aluminum foam protected system for URM wall against blast loads.
