The thermodynamics and kinetics of the reaction between Titanium powder and 7075 aluminum alloy were investigated to assess the possibility of preparing TiA1J7075 composites by in-situ synthesis method. Results show t...The thermodynamics and kinetics of the reaction between Titanium powder and 7075 aluminum alloy were investigated to assess the possibility of preparing TiA1J7075 composites by in-situ synthesis method. Results show that Ti and A1 melt can form TiA13 spontaneously, which is considered as a reinforced phase of the matrix. Measurements such as XRD, SEM, and EDX were performed to characterize the as-synthesized samples, and results confirmed the formation of TiA13 in aluminum matrix composites. The reactive kinetics was controlled by three main factors, which are the system temperature, particle size of Ti, and the thickness of external diffusion layer.展开更多
In this work,the Sn-58Bi(weight percent) eutectic alloy was directionally solidified at a constant temperature gradient(G = 12 K.mm-1) with different growth rates using a Bridgman type directional solidification furna...In this work,the Sn-58Bi(weight percent) eutectic alloy was directionally solidified at a constant temperature gradient(G = 12 K.mm-1) with different growth rates using a Bridgman type directional solidification furnace.A lamellar microstructure was observed in the Sn-58Bi samples.The lamellar spacing and micro-hardness of longitudinal and transversal sections were measured.The values of lamellar spacing of both longitudinal and transversal sections decrease with an increase in growth rate.The microhardness increases with an increase in the growth rate and decreases with an increase in the lamellar spacing.The dependence of lamellar spacing on growth rate,and micro-hardness on both growth rate and lamellar spacing were obtained by linear regression analysis.The relationships between the lamellar spacing and growth rate,microhardness and growth rate,and micro-hardness and lamellar spacing for transversal and longitudinal sections of Sn-58Bi eutectic alloy were given.The fitted exponent values obtained in this work were compared with the previous similar experimental results and a good agreement was obtained.展开更多
Cerenkov luminescence imaging(CLI)is a non-invasive imaging technique showing immense promise for clinical translation.However,weak signal intensity and poor tissue penetration depth are two shortcomings that limit it...Cerenkov luminescence imaging(CLI)is a non-invasive imaging technique showing immense promise for clinical translation.However,weak signal intensity and poor tissue penetration depth are two shortcomings that limit its clinical applications.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.51165032,51102131)the Innovative Group of Science and Technology of College of Jiangxi Province(No.00008713)
文摘The thermodynamics and kinetics of the reaction between Titanium powder and 7075 aluminum alloy were investigated to assess the possibility of preparing TiA1J7075 composites by in-situ synthesis method. Results show that Ti and A1 melt can form TiA13 spontaneously, which is considered as a reinforced phase of the matrix. Measurements such as XRD, SEM, and EDX were performed to characterize the as-synthesized samples, and results confirmed the formation of TiA13 in aluminum matrix composites. The reactive kinetics was controlled by three main factors, which are the system temperature, particle size of Ti, and the thickness of external diffusion layer.
基金financially supported by the China Postdoctoral Science Foundation(No.20110491492)Nature Science Foundation of Jiangxi Province(Nos.20114BAB216017,20114BAB206021)the Science and Technology Project of Jiangxi Department of Education(No.GJJ12035)
文摘In this work,the Sn-58Bi(weight percent) eutectic alloy was directionally solidified at a constant temperature gradient(G = 12 K.mm-1) with different growth rates using a Bridgman type directional solidification furnace.A lamellar microstructure was observed in the Sn-58Bi samples.The lamellar spacing and micro-hardness of longitudinal and transversal sections were measured.The values of lamellar spacing of both longitudinal and transversal sections decrease with an increase in growth rate.The microhardness increases with an increase in the growth rate and decreases with an increase in the lamellar spacing.The dependence of lamellar spacing on growth rate,and micro-hardness on both growth rate and lamellar spacing were obtained by linear regression analysis.The relationships between the lamellar spacing and growth rate,microhardness and growth rate,and micro-hardness and lamellar spacing for transversal and longitudinal sections of Sn-58Bi eutectic alloy were given.The fitted exponent values obtained in this work were compared with the previous similar experimental results and a good agreement was obtained.
文摘Cerenkov luminescence imaging(CLI)is a non-invasive imaging technique showing immense promise for clinical translation.However,weak signal intensity and poor tissue penetration depth are two shortcomings that limit its clinical applications.
