Solidification simulation of manufacturing shaped casting which plays an important role in assuring the soundness and quality of castings, in minimizing the trial production time and in reducing the manufacturing cost...Solidification simulation of manufacturing shaped casting which plays an important role in assuring the soundness and quality of castings, in minimizing the trial production time and in reducing the manufacturing cost becomes one of the hottest topics of the new research frontiers of foundry technology at home and abroad. Practical three dimensional computer numerical simulation system for temperature distribution during solidification as well as shrinkage cavity and porosity prediction has already been put into application all over the world. Further fundamental researches on fluid flow, thermal stress and micro-modeling as well as practical approaches of numerical simulation of solidification process of shaped castings for routine analysis of foundry industry are still underway.展开更多
In order to study the thermal stresses at the mushy zone, a three dimensional rheological model [H]-[H\N]-[N\S] including elastic, visco-elastic and visco-plastic elements was established, its algorithm and codes for ...In order to study the thermal stresses at the mushy zone, a three dimensional rheological model [H]-[H\N]-[N\S] including elastic, visco-elastic and visco-plastic elements was established, its algorithm and codes for finite element method were also developed. A FDM/FEM integrated analysis system of thermal stresses was built based on the integration of this procedure with thermal analysis by finite difference method. A steel sample casting with a hot spot was simulated in order to validate this system, and the calculated and experimental results were in good agreement.展开更多
The effects of metallurgical and processing parameters on the formation of solidification shrinkage in ductile iron have been studied, considering the parameters of carbon equivalent, inoculation, casting modulus and ...The effects of metallurgical and processing parameters on the formation of solidification shrinkage in ductile iron have been studied, considering the parameters of carbon equivalent, inoculation, casting modulus and pouring temperature within specific ranges of these variables. Based on the orthogonal experiments, the metallurgical and processing parameters of the minimum casting shrinkage and the maximum casting shrinkage were obtained, and the effects of metallurgical and processing parameters on the formation of shrinkage cavities and porosities in ductile iron castings were discussed. A regression equation relating these variables to the formation of shrinkage was derived based upon the orthogonal experiments conducted.展开更多
Zn-Mg-Y and Mg-Zn-Y-Zr ingots with different chemical compositions were; investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The icosahedral phases were found in all alloys studied in p...Zn-Mg-Y and Mg-Zn-Y-Zr ingots with different chemical compositions were; investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The icosahedral phases were found in all alloys studied in present work under the as-cast conditions. There are nearly all quasicrystal phases with some MgZn2 Laves phase in a Zn-28.31Mg-13.80Y alloy (wt pet). After annealing at 400 degrees C for 8 h, the quasicrystal phases transformed to an fee ''W'' phase in an Mg-5.57Zn-1.08Y-0.60Zr alloy (wt pet).展开更多
文摘Solidification simulation of manufacturing shaped casting which plays an important role in assuring the soundness and quality of castings, in minimizing the trial production time and in reducing the manufacturing cost becomes one of the hottest topics of the new research frontiers of foundry technology at home and abroad. Practical three dimensional computer numerical simulation system for temperature distribution during solidification as well as shrinkage cavity and porosity prediction has already been put into application all over the world. Further fundamental researches on fluid flow, thermal stress and micro-modeling as well as practical approaches of numerical simulation of solidification process of shaped castings for routine analysis of foundry industry are still underway.
文摘In order to study the thermal stresses at the mushy zone, a three dimensional rheological model [H]-[H\N]-[N\S] including elastic, visco-elastic and visco-plastic elements was established, its algorithm and codes for finite element method were also developed. A FDM/FEM integrated analysis system of thermal stresses was built based on the integration of this procedure with thermal analysis by finite difference method. A steel sample casting with a hot spot was simulated in order to validate this system, and the calculated and experimental results were in good agreement.
文摘The effects of metallurgical and processing parameters on the formation of solidification shrinkage in ductile iron have been studied, considering the parameters of carbon equivalent, inoculation, casting modulus and pouring temperature within specific ranges of these variables. Based on the orthogonal experiments, the metallurgical and processing parameters of the minimum casting shrinkage and the maximum casting shrinkage were obtained, and the effects of metallurgical and processing parameters on the formation of shrinkage cavities and porosities in ductile iron castings were discussed. A regression equation relating these variables to the formation of shrinkage was derived based upon the orthogonal experiments conducted.
文摘Zn-Mg-Y and Mg-Zn-Y-Zr ingots with different chemical compositions were; investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The icosahedral phases were found in all alloys studied in present work under the as-cast conditions. There are nearly all quasicrystal phases with some MgZn2 Laves phase in a Zn-28.31Mg-13.80Y alloy (wt pet). After annealing at 400 degrees C for 8 h, the quasicrystal phases transformed to an fee ''W'' phase in an Mg-5.57Zn-1.08Y-0.60Zr alloy (wt pet).
