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Wang Y.,Harbin Institute of Technology | Wu S.,Harbin Institute of Technology | Niu L.,Hebei Institute of Architecture and Civil Engineering | Xue X.,Harbin Institute of Technology | And 2 more authors.
Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture | Year: 2014

In order to reduce serious tendency of the shrinkage porosity in ZL205A alloy, the design of experiment technique, Taguchi method is introduced to optimize the process parameters of cylindrical shell ZL205A alloy parts produced by low-pressure die casting in this article. The effect of pouring temperature, filling time and packing pressure on the shrinkage porosity in ZL205A castings is investigated using the orthogonal array and Advanced Porosity Model in ProCAST to calculate the volume of shrinkage porosity. The effectiveness of selected casting parameters in reducing the shrinkage porosity in cylindrical shell ZL205A casting is verified through analysis of signal-to-noise ratio and analysis of variance. Numerical results indicate that the optimized process parameters, including a pouring temperature of 725 °C, filling time of 20 s and packing pressure of 175 kPa, can be used to reduce the formation of shrinkage porosity in ZL205A castings. © IMechE 2014.

Fan X.,Harbin Institute of Technology | Wang L.,Harbin Institute of Technology | Du Z.,Tianjin Long March Launch Vehicle Manufacturing Co. | Su Y.,Harbin Institute of Technology | And 6 more authors.
Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering | Year: 2015

Ansoft software was used to simulate the electromagnetic force of the cylindrical thin-walled casts under the action of traveling magnetic field, and the influence of excitation currents on mold-filling capacity of different alloys and surface depression of thin-walled casts were investigated. The results show that the magnetic field remarkably influences the mold-filling capacity of alloys and the casting surface depression simultaneously. The mold-filling capacity and the possibility of the surface depression are increased with the square of the excitation current intensity increasing. Under the same excitation current intensity, the excitation current frequency has the optimal value to the mold-filling capacity; the possibility of the casting surface depression decreases along with its decrease below 1000 Hz. © 2015, Science Press. All right reserved.

Fan X.-Y.,Harbin Institute of Technology | Wang L.,Harbin Institute of Technology | Du Z.-Q.,Tianjin Long March Launch Vehicle Manufacturing Co. | Zhang J.-B.,China Shoudu Space Machinery Company | And 4 more authors.
China Foundry | Year: 2015

The effect of excitation current intensity on the mechanical properties of ZL205A castings solidified under a traveling magnetic field was studied. The results of the experiment indicate that the excitation current intensity of the traveling magnetic field has a great influence on the mechanical properties of the ZL205A castings. When the excitation current intensity is 15 A, the tensile strength and elongation of ZL205A alloy castings increase 27.2% and 67.7%, respectively, compared with those of the same alloy solidified under gravity. The improvement of mechanical properties is attributed to the decrease of micro-porosity in the alloy. Under the traveling magnetic field, the feeding pressure in the alloy melt before solidification can be enhanced due to the electromagnetic force. Moreover, the melt flow induced by the traveling magnetic field can decrease the temperature gradient. The feeding resistance will be increased because the temperature gradient decrease. So traveling magnetic field has an optimum effect on feeding. © 2015, Foundry Journal Agency. All rights reserved.

Wu S.,Harbin Institute of Technology | Wang Y.,Harbin Institute of Technology | Wu G.,China Shoudu Space Machinery Company | Zhang J.,China Shoudu Space Machinery Company | Xiao W.,China Shoudu Space Machinery Company
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys | Year: 2012

The temperature field, shrinkage porosity (hole) in the ZL205A alloy shell castings during low pressure casting process were visualized through numerical simulation. The results show that the desirable temperature filed can be obtained and tendency of shrinkage porosity in the defect location of the shell can be reduced by using the chill and riser, adding the number of slit runners from eight to ten and decreasing the length of feeding distance from 200 mm to 157 mm. Comparison with the experimental results indicates that the scheme of chill combining with riser is reasonable and feasible.

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