A computer system for displacement sensor is developed to obtain the real-time curve of the liquid porosity of molten Al alloy foam. The relationship between the curve ofP I-t and the change of the shape of the cells ...A computer system for displacement sensor is developed to obtain the real-time curve of the liquid porosity of molten Al alloy foam. The relationship between the curve ofP I-t and the change of the shape of the cells (spherical, similar spherical and polygonal) in the foaming process is analyzed. The changes of cell diameter and cell wall thickness are studied. And the the controlling methods of a new Al alloy foam with spherical pores, low porosity and high strength are developed on this basis. Also, the stress-strain curve during compressive deformation and energy absorption characteristics are investigated and compared with polygonal pore Al alloy foam with high porosity. Keywords spherical pore - low porosity - high strength - interface shifting - Al alloy foam These authors contributed equally to this work.展开更多
Two steps foaming (TSF) technique was proposed to prepare shaped Al alloy foam. Based on the thermal decomposition kinetics equation of titanium hydride, the relationship be-tween two steps thermal decomposition kinet...Two steps foaming (TSF) technique was proposed to prepare shaped Al alloy foam. Based on the thermal decomposition kinetics equation of titanium hydride, the relationship be-tween two steps thermal decomposition kinetics of titanium hydride and two steps foaming Al alloy melt was studied. Two steps thermal decomposition curve of titanium hydride under in-creasing and constant temperature was calculated respectively. The hydrogen mass needed in the second foaming step was also calculated. Results showed that the hydrogen mass of the second thermal decomposition of titanium hydride is enough for the second foaming step in the condition of as-received Al melt foaming. Experimental and theoretical results indicate that two steps foaming technique can be used to prepare Al alloy foam with high porosity, shaped com-ponents and sandwich with Al alloy foam core.展开更多
Due to the demand of high-tech Al alloy foam with spherical pores, high strength and high energy-absorption capacity has become one of the research foci. The aim of this study is to ascertain the growth regularity of ...Due to the demand of high-tech Al alloy foam with spherical pores, high strength and high energy-absorption capacity has become one of the research foci. The aim of this study is to ascertain the growth regularity of spherical foam in Al alloy melt. Three-dimensional packing model such as face-centered cubic is established to study the spherical foam growth. Theoretical results are compared with experimental ones, and the face-centered cubic model corresponds well with the experiment. It is reasonable to assume that the pores have the same radius, the total pore number keeps unchanged and spherical foam grows with face-centered cubic packing mode. This study presents a useful help to control the average pore radius and film thickness.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.50231010,50081002,90205005 and 19982001).
文摘A computer system for displacement sensor is developed to obtain the real-time curve of the liquid porosity of molten Al alloy foam. The relationship between the curve ofP I-t and the change of the shape of the cells (spherical, similar spherical and polygonal) in the foaming process is analyzed. The changes of cell diameter and cell wall thickness are studied. And the the controlling methods of a new Al alloy foam with spherical pores, low porosity and high strength are developed on this basis. Also, the stress-strain curve during compressive deformation and energy absorption characteristics are investigated and compared with polygonal pore Al alloy foam with high porosity. Keywords spherical pore - low porosity - high strength - interface shifting - Al alloy foam These authors contributed equally to this work.
基金supported by the National Natural Science Foundation of China(Grant Nos.50471031,50231010,50081002&19982001)Foundation of Excellent Doctoral Dissertation of Southeast University(Grant No.YBJJ0409)National Project 973(Grant No.2006CB601201).
文摘Two steps foaming (TSF) technique was proposed to prepare shaped Al alloy foam. Based on the thermal decomposition kinetics equation of titanium hydride, the relationship be-tween two steps thermal decomposition kinetics of titanium hydride and two steps foaming Al alloy melt was studied. Two steps thermal decomposition curve of titanium hydride under in-creasing and constant temperature was calculated respectively. The hydrogen mass needed in the second foaming step was also calculated. Results showed that the hydrogen mass of the second thermal decomposition of titanium hydride is enough for the second foaming step in the condition of as-received Al melt foaming. Experimental and theoretical results indicate that two steps foaming technique can be used to prepare Al alloy foam with high porosity, shaped com-ponents and sandwich with Al alloy foam core.
基金the National Natural Science Foundation of China(Grant Nos.50471031,50231010,50081002&19982001)Foundation of Excellent Doctoral Dissertation of Southeast University(Grant No.YBJJ0409) National 973 Project.
文摘Due to the demand of high-tech Al alloy foam with spherical pores, high strength and high energy-absorption capacity has become one of the research foci. The aim of this study is to ascertain the growth regularity of spherical foam in Al alloy melt. Three-dimensional packing model such as face-centered cubic is established to study the spherical foam growth. Theoretical results are compared with experimental ones, and the face-centered cubic model corresponds well with the experiment. It is reasonable to assume that the pores have the same radius, the total pore number keeps unchanged and spherical foam grows with face-centered cubic packing mode. This study presents a useful help to control the average pore radius and film thickness.
