With the experiment and finite element simulation, the influences of power ultrasonic on the solidification structure of 7050 aluminum alloy ingot in semi-continuous casting were researched, and the effects of casting...With the experiment and finite element simulation, the influences of power ultrasonic on the solidification structure of 7050 aluminum alloy ingot in semi-continuous casting were researched, and the effects of casting speed on solidification structure in ultrasonic field were also analyzed. The experiment and simulation results show that the solidification structure of the ingot is homogeneously distributed, and its grain size is obviously refined at ultrasonic power of 240 W. The average grain sizes, which can be seen from the Leica microscope, are less than 100 μm. When the casting speed is 45-50 mm/min, the best grain refinement is obtained.展开更多
Solidification structure is critical in the control of the mechanical properties and quality during the continuous casting process. The thermo-physical properties of 13 Cr steel added some rare metals, such as Mo, V, ...Solidification structure is critical in the control of the mechanical properties and quality during the continuous casting process. The thermo-physical properties of 13 Cr steel added some rare metals, such as Mo, V, Nb, are measured to better understand the solidification structure of 13 Cr bloom. A computational model using CA-FE(cellular automation-finite element) method coupled with heat transfer model is developed to describe the solidification structure in continuous casting process. It is found that the calculated solidification structure is in good agreement with the observed data. The influence of casting speed and superheat on the solidification structure of the bloom is studied in detail. In order to obtain more equiaxed crystal ratio and low degree of the segregation in the bloom, the optimized casting speed 0.6 m/min and superheat less than 25 °C are determined for the caster. Using the optimized manufacturing parameters, these samples are 60% with the equiaxed zone ratio of 8%–10% and below the degree of segregation 1.05.展开更多
The solidification microstructure,fracture morphologies,and mechanical properties of an Al-18Si alloy and alloys modified with Al-5Ti and Al-3P master alloys were investigated using an optical microscope,scanning elec...The solidification microstructure,fracture morphologies,and mechanical properties of an Al-18Si alloy and alloys modified with Al-5Ti and Al-3P master alloys were investigated using an optical microscope,scanning electron microscope,and an electronic universal testing machine.The results show that additions of Al-5Ti and Al-3P have significant effects on the size and area fraction of the primary Si and the mechanical properties of the Al-18Si alloy.Compared to the Al-18Si alloy modified with 0.6 wt%Al-5Ti at 850°C,when the Al-18Si alloy was modified with 0.3 wt%Al-5Ti and 0.5 wt%Al-3P at the same temperature,the average size of the primary Si decreased from 39 to 14μm and the area fraction increased from 9.5%to 11.6%.The biggest influencing factor on the tensile strength and elongation of the Al-18Si alloy is the addition of Al-3P,followed by the modification temperature and the addition of Al-5Ti.At a modification temperature of 850°C,the tensile strength and elongation of the Al-18Si alloy modified with 0.3 wt%Al-5Ti+0.5 wt%Al-3P increased by 19.6%and 88.6%,respectively compared to that of the Al-18Si alloy modified with 0.6 wt%Al-5Ti.展开更多
基金Project(2010CB731700) supported by the National Basic Research Program of China
文摘With the experiment and finite element simulation, the influences of power ultrasonic on the solidification structure of 7050 aluminum alloy ingot in semi-continuous casting were researched, and the effects of casting speed on solidification structure in ultrasonic field were also analyzed. The experiment and simulation results show that the solidification structure of the ingot is homogeneously distributed, and its grain size is obviously refined at ultrasonic power of 240 W. The average grain sizes, which can be seen from the Leica microscope, are less than 100 μm. When the casting speed is 45-50 mm/min, the best grain refinement is obtained.
基金Projects(51274057,51474057) supported by the National Natural Science Foundation of ChinaProject(2012AA03A508) supported by the High-tech Research and Development Program of China
文摘Solidification structure is critical in the control of the mechanical properties and quality during the continuous casting process. The thermo-physical properties of 13 Cr steel added some rare metals, such as Mo, V, Nb, are measured to better understand the solidification structure of 13 Cr bloom. A computational model using CA-FE(cellular automation-finite element) method coupled with heat transfer model is developed to describe the solidification structure in continuous casting process. It is found that the calculated solidification structure is in good agreement with the observed data. The influence of casting speed and superheat on the solidification structure of the bloom is studied in detail. In order to obtain more equiaxed crystal ratio and low degree of the segregation in the bloom, the optimized casting speed 0.6 m/min and superheat less than 25 °C are determined for the caster. Using the optimized manufacturing parameters, these samples are 60% with the equiaxed zone ratio of 8%–10% and below the degree of segregation 1.05.
基金Project(51571039) supported by the National Natural Science Foundation of China
文摘The solidification microstructure,fracture morphologies,and mechanical properties of an Al-18Si alloy and alloys modified with Al-5Ti and Al-3P master alloys were investigated using an optical microscope,scanning electron microscope,and an electronic universal testing machine.The results show that additions of Al-5Ti and Al-3P have significant effects on the size and area fraction of the primary Si and the mechanical properties of the Al-18Si alloy.Compared to the Al-18Si alloy modified with 0.6 wt%Al-5Ti at 850°C,when the Al-18Si alloy was modified with 0.3 wt%Al-5Ti and 0.5 wt%Al-3P at the same temperature,the average size of the primary Si decreased from 39 to 14μm and the area fraction increased from 9.5%to 11.6%.The biggest influencing factor on the tensile strength and elongation of the Al-18Si alloy is the addition of Al-3P,followed by the modification temperature and the addition of Al-5Ti.At a modification temperature of 850°C,the tensile strength and elongation of the Al-18Si alloy modified with 0.3 wt%Al-5Ti+0.5 wt%Al-3P increased by 19.6%and 88.6%,respectively compared to that of the Al-18Si alloy modified with 0.6 wt%Al-5Ti.
