To investigate the possibility of inoculating eutectic cells, a novel AI-10Si-2Fe master alloy was synthesized and tested in Sr-modified A356 alloy. The new master alloy that consists of reAl, Si andβ-AIsFeSi phases ...To investigate the possibility of inoculating eutectic cells, a novel AI-10Si-2Fe master alloy was synthesized and tested in Sr-modified A356 alloy. The new master alloy that consists of reAl, Si andβ-AIsFeSi phases was prepared by a casting process, and the silicon phase was found to grow epitaxially from theβ-AIsFeSi particles. The inoculation efficiency of the new master alloy on Sr-modified A356 alloy has been investigated by quenching experiment and thermal analysis. With the addition of the new master alloy, the area density of eutectic cells is effectively increased by 100% and the eutectic growth temperature is increased by 1.5 ℃. Therefore, the new master alloy is deduced to introduce nucleating substrates for eutectic cells and to refine the eutectic cells in Sr-modifled A356 alloy. There is no poisonous interaction between the AI-10Si-2Fe master alloy and the Sr in this study. Consequently, the mechanical properties have been improved by the addition of the new master alloy.展开更多
With the high-temperature viscometer and magnetic susceptibility measurement device designed by our group,the viscosity and the magnetic susceptibility of the Cu65Sn35 melt were measured during the cooling process.An ...With the high-temperature viscometer and magnetic susceptibility measurement device designed by our group,the viscosity and the magnetic susceptibility of the Cu65Sn35 melt were measured during the cooling process.An anomalous change can be found in the curves of viscosity and magnetic susceptibility at a certain temperature.The structure of the melt was studied by the high-temperature X-ray diffractometer.The anomalous change also can be found in the pair distribution function,correlation radius,and coordination number at the approximate tem-perature,which shows the microstructural change of the Cu65Sn35 melt.From the results,it was confirmed that the Cu6Sn5 compound occurs in the melt,which leads to the structural change of the melt.展开更多
The liquid structure of Al71.6 Ge28.4 eutectic alloy was studied by X-ray diffractometer.For the liquid alloy Al71.6 Ge28.4,the structure has no change while the order increases with the decreasing temperature from 11...The liquid structure of Al71.6 Ge28.4 eutectic alloy was studied by X-ray diffractometer.For the liquid alloy Al71.6 Ge28.4,the structure has no change while the order increases with the decreasing temperature from 1150°C to 550°C.Meanwhile,the correlation between liquid structure and solid structure has also been analyzed by "the nanocrystal model".It is shown that the melt consists of 72.8% α clusters and 27.2% β clusters,but the liquid structure and solid structure have striking difference,which is one of the reasons to obtain a large undercooling easily for this alloy.展开更多
基金supported by the National Natural Science Foundation of China(No.51371109)
文摘To investigate the possibility of inoculating eutectic cells, a novel AI-10Si-2Fe master alloy was synthesized and tested in Sr-modified A356 alloy. The new master alloy that consists of reAl, Si andβ-AIsFeSi phases was prepared by a casting process, and the silicon phase was found to grow epitaxially from theβ-AIsFeSi particles. The inoculation efficiency of the new master alloy on Sr-modified A356 alloy has been investigated by quenching experiment and thermal analysis. With the addition of the new master alloy, the area density of eutectic cells is effectively increased by 100% and the eutectic growth temperature is increased by 1.5 ℃. Therefore, the new master alloy is deduced to introduce nucleating substrates for eutectic cells and to refine the eutectic cells in Sr-modifled A356 alloy. There is no poisonous interaction between the AI-10Si-2Fe master alloy and the Sr in this study. Consequently, the mechanical properties have been improved by the addition of the new master alloy.
基金the National Natural Science Foundation of China (Grant Nos. 50395101and 50571052)
文摘With the high-temperature viscometer and magnetic susceptibility measurement device designed by our group,the viscosity and the magnetic susceptibility of the Cu65Sn35 melt were measured during the cooling process.An anomalous change can be found in the curves of viscosity and magnetic susceptibility at a certain temperature.The structure of the melt was studied by the high-temperature X-ray diffractometer.The anomalous change also can be found in the pair distribution function,correlation radius,and coordination number at the approximate tem-perature,which shows the microstructural change of the Cu65Sn35 melt.From the results,it was confirmed that the Cu6Sn5 compound occurs in the melt,which leads to the structural change of the melt.
基金supported by the National Natural Science Foundation of China (Grant Nos.50395101 and 50571052)
文摘The liquid structure of Al71.6 Ge28.4 eutectic alloy was studied by X-ray diffractometer.For the liquid alloy Al71.6 Ge28.4,the structure has no change while the order increases with the decreasing temperature from 1150°C to 550°C.Meanwhile,the correlation between liquid structure and solid structure has also been analyzed by "the nanocrystal model".It is shown that the melt consists of 72.8% α clusters and 27.2% β clusters,but the liquid structure and solid structure have striking difference,which is one of the reasons to obtain a large undercooling easily for this alloy.
