Papers by Author: Hong Sheng Ding

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Authors: Jie Ren Yang, Rui Run Chen, Hong Sheng Ding, Jing Jie Guo, Heng Zhi Fu
Abstract: This paper has systematically studied the evolving process of column crystals of Ti46Al0.5W0.5Si alloys that is directionally solidified by rectangular cold crucible. The results showed that: the solid/liquid interface presented convex to the liquid metal due to the complicated influences by cold crucible. Overheating temperature and new crystal nucleus had great effects on the growth continuity and the stability of column crystals. Furthermore, the precipitation phases have been studied. As a result, the methods for controlling growing process of columnar crystals have been submitted, which are playing a critical role in optimizing experimental parameters and devising the construction-elements of cold crucible.
Authors: Hong Sheng Ding, Rui Run Chen, Yan Li Wang, Heng Zhi Fu, Jing Jie Guo, Wei Sheng Bi, Jun Jia
Authors: Feng Huang, Rui Run Chen, Jing Jie Guo, Hong Sheng Ding, Yan Qing Su, Heng Zhi Fu
Abstract: Effects of parameters on the stability of silicon melt pool in cold crucible continuous casting were discussed. The results indicate that the extinguishing of induction heating is mainly caused by the side wall feeding, low superheat degree and volume of the pool. The hot melt splashes are caused by the higher input power and uncompletely melted silicon of the dome top surface. The pool was shown to be stabilized as the raw materials were fed in the center area of the dome surface, the superheat degree and volume of the pool were properly increased, the pool was controlled in the effective heating range of the coil and the input power was set properly
Authors: Rui Run Chen, Feng Huang, Jing Jie Guo, Hong Sheng Ding, Yan Qing Su, Jie Ren Yang, Heng Zhi Fu
Abstract: The effects of technical parameters on initial silicon melting in cold crucible continuous casting were studied. These parameters include the materials, the shape and the position of the base, the mass of the silicon that set on the top of the base. Through experimental and theoretical analysis, the optimized parameters were finally given: the base graphite with obconical shaped should be put at the level of the second turn of the coil, and the initial silicon with 10g should be put on the base. The mechanism of these parameters affecting on the initial melting are discussed and revealed.
Authors: Hong Sheng Ding, Ge Nie, Yong Zhe Wang, Rui Run Chen, Jing Jie Guo, Heng Zhi Fu
Abstract: Developing high performance aero-engines usually depends on the development of new candidate materials with charming properties such as relatively light-weight, good high temperature strength and environmental resistance. Fortunately, γ-TiAl alloys were followed into this catalogue that they offer a significant potentiality for weight savings. Recently, in order to improve their low room temperature plasticity, a motive technology called electromagnetic cold crucible directional solidification technology for preparation γ-TiAl alloy ingots with directional growth structure was put forward by our group. By the approach, TiAl ingots with controllable lamellar structures and less impurity contaminations are obtained. Typically, Ti-46Al-0.5W-0.5Si and Ti-47Al-2Cr-2Nb were performed with respect to compositions and solidification parameters. As a result, Ti-46Al-0.5W-0.5Si DS-samples exhibit good combination of mechanical properties at room temperature in TS of 500MPa and EL of 2% in average. Meanwhile TS of DS Ti-47Al-2Cr-2Nb reaches 650 MPa and EL exceeds 3%.
Authors: Feng Huang, Rui Run Chen, Jing Jie Guo, Hong Sheng Ding
Abstract: The electromagnetic continuous pulling is a newly growth technology as a promising process for silicon preparation, start-up heating is necessary for the semiconductivity of silicon at room temperature. Investigations were carried out to study this process in a square crucible with the frequency of 50kHz, details of the experimental procedure were given, the affecting factors, electrical performance and heat explosion problems during the process were measured and discussed. The results indicated that the best conditions for the preheating were the central position of the base in the coil, the higher power and the proper primary mass of silicon setting. The electrical performance indirectly showed the pool conditions and so it can be effectively used to control the melting operation.
Authors: Feng Huang, Rui Run Chen, Jing Jie Guo, Hong Sheng Ding, Yan Qing Su, Jie Ren Yang, Heng Zhi Fu
Abstract: A square shaped silicon ingot was cast by cold crucible continuous casting. The grain growth behaviors during different growth stages were investigated. In the first, grains nucleate at the base surface in the centre and in the three phase junction at periphery, and then grow upwards and inclined upwards separately. In the second, grain grow competitively, two distinguished zones are formed. In the final, a cap is formed on the liquid free surface, and precipitates are present.
Authors: Rui Run Chen, Hong Sheng Ding, Jing Jie Guo, Yan Qing Su, Heng Zhi Fu
Abstract: The ingot of Ti47Al alloy was prepared by a newly developed rapid directional solidification, the microstructure and compressive properties of the ingot was observed and tested. The results show that the macrostructure consisted mainly of coarse columnar grains parallel to the axial direction, with the size of 0.5mm wide and 10mm in length. The direction of lamellar is almost perpendicular to the growth direction in the longitudinal section and no dendritic core is found. The average ultimate compressive strength of the specimens with grain growth parallel/perpendicular to the compressive direction is 1233.3 and 861.7 MPa respectively. The fracture mode for specimens with grain growth parallel to the compressive direction exhibits predominantly translamellar fracture, however, that for specimens with grain growth perpendicular to the compressive direction exhibits predominantly delamenation or interlamellar fracture.
Authors: Jing Jie Guo, G.H. Liu, Yan Qing Su, Hong Sheng Ding, Jun Jia, Heng Zhi Fu
Abstract: The ratio of skull weight to charge weight (Rs) and the skull size during the induction skull melting (ISM) processing of TiAl alloy were investigated. The effects of inputting power, charge weight, and holding time on them were studied theoretically. An experiment was carried out. The theoretical and experimental results are in good agreement.
Authors: Rui Run Chen, Jie Ren Yang, Hong Sheng Ding, Jing Jie Guo, Yan Qing Su, Feng Huang, Heng Zhi Fu
Abstract: In this study, Ti46Al0.5W0.5Si ingots were directionally solidified by a near-rectangular cold crucible under different process parameters. These process parameters include the electromagnetic stirring, the crucible configuration and the molten drop, all of them have important effect on the S/L interface. The effects of the parameters on the solid/liquid (S/L) interface morphology were investigated, and the mechanisms of the parameters influencing the S/L interface were discussed and revealed. Results showed that the typical S/L interface of the ingots was presented as a curved ‘W-type’ shape. The uneven temperature distribution in the front of the solidified interface is the main reason for a curved S/L interface. Further, the requirements for obtaining a planar S/L interface in the process of cold crucible directional solidification were given, which provided a guide for the future work.
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