The design of the cooling system of injection molds directly affects both productivity and the quality of the final part. Using the cooling process CAE system to instruct the mold design, the efficiency and quality ...The design of the cooling system of injection molds directly affects both productivity and the quality of the final part. Using the cooling process CAE system to instruct the mold design, the efficiency and quality of design can be improved greatly. At the same time, it is helpful to confirm the cooling system structure and optimize the process conditions. In this paper, the 3D surface model of mold cavity is used to replace the middle-plane model in the simulation by Boundary Element Method, which break the bottleneck of the application of the injection molding simulation softwares base on the middle-plane model. With the improvements of this paper, a practical and commercial simulation software of injection molding cooling process named as HsCAE3D6.0 is developed.展开更多
On the basis of the comprehensive analysis about the automatic generation of the injection mold parting surface, the parting surface design method which introduces knowledge and case-based reasoning （CBR） into the c...On the basis of the comprehensive analysis about the automatic generation of the injection mold parting surface, the parting surface design method which introduces knowledge and case-based reasoning （CBR） into the computer-aided design is described by combining with the actual characteristic in injection mold design, and the design process of case-based reasoning method is also given. A case library including the information of parting surface is built with the index of main shape features, The automatic design of the mold parting surface is realized combined with the forward-reasoning method and the similarity solution procedure. The rule knowledge library is also founded including the knowledge, principles and experiences for parting surface design. An example is used to show the validity of the method, and the quality and the efficiency of the mold design are improved.展开更多
Deformation of casting during the solidification process has puzzled many engineers and scientists for years. In order to attain the goal of near-net forming by casting, numerical simulation is a powerful tool. Tradit...Deformation of casting during the solidification process has puzzled many engineers and scientists for years. In order to attain the goal of near-net forming by casting, numerical simulation is a powerful tool. Traditional methods compute the thermal stress of both the casting and the mold. This method suffers the problem of massive calculation and failure of convergence. This paper proposes an improved Mold Surface Element Method, the main idea of which is to use the surface elements instead of body elements to express the interactions between the casting and the mold. The proposed method shows a high computation efficiency and provides satisfactory precision for engineering. Two practical casting products were used to verify the proposed method. The simulated results agree well with those observed in practical products. The proposed method is believed to benefit production practice and to provide theoretical guidance.展开更多
The effects of the wavelength and orientation of machined grooves on a mold surface, casting speed, and melt superheat on the formation of surface marks on as-cast ingots were studied with an immersion casting tester ...The effects of the wavelength and orientation of machined grooves on a mold surface, casting speed, and melt superheat on the formation of surface marks on as-cast ingots were studied with an immersion casting tester and copper mold chill blocks. The mold surface topographies included a polished smooth surface, and those with machined unidirectional parallel contoured grooves oriented either parallel (vertical) or perpendicular (horizontal) to the casting direction. The unidirectional grooves were 0.232 mm deep with wavelength or spacing between 1 and 15 mm. The casting speed and melt superheat were between 1 and 200 mm/s, and 10 and 50 K, respectively. Two primary types of surface marks were observed on ingots cast with the copper mold with smooth surface topography, namely the finer and closely spaced ripples (Type I), and the widely spaced but coarser laps (Type II). The latter were more prevalent at the higher casting speeds and melt superheats. Qualitatively, formation of both types of surface marks on the as-cast ingots of the aluminum alloy 3003 appeared to be alleviated by increase in casting speed and melt superheat, and by the use of molds with grooved surface topography. In fact, casting with a mold surface with 1 mm spaced grooves that are perpendicular to the casting direction eliminated the formation of surface marks at casting speeds greater than 1 mm/s. It also improved the uniformity of the ingot subsurface microstructure and eliminated the associated subsurface segregation.展开更多
The fact that the amount of the mold flux components differs at differentlocations on the cracking surface indicates that the longitudinal surface cracks are initiallyformed in the mold and are enlarged in the seconda...The fact that the amount of the mold flux components differs at differentlocations on the cracking surface indicates that the longitudinal surface cracks are initiallyformed in the mold and are enlarged in the secondary cooling zone. Based on the hot ductilitymeasurement of two typical container used steels, it is known that the steels are in severeembrittlement state in the temperature range of 825-775 deg C. By means of increasing Cr/Ni platingthickness on the upper part of the mold, reducing mold heat flux, adopting new secondary coolingpattern, etc., the occurrence of the surface longitudinal cracks on the steel CC (continuouscasting) slabs has been significantly reduced.展开更多
基金Supported by NationalNatural Science FoundationCouncil of the People’s Republic of China (20490224)
文摘The design of the cooling system of injection molds directly affects both productivity and the quality of the final part. Using the cooling process CAE system to instruct the mold design, the efficiency and quality of design can be improved greatly. At the same time, it is helpful to confirm the cooling system structure and optimize the process conditions. In this paper, the 3D surface model of mold cavity is used to replace the middle-plane model in the simulation by Boundary Element Method, which break the bottleneck of the application of the injection molding simulation softwares base on the middle-plane model. With the improvements of this paper, a practical and commercial simulation software of injection molding cooling process named as HsCAE3D6.0 is developed.
文摘On the basis of the comprehensive analysis about the automatic generation of the injection mold parting surface, the parting surface design method which introduces knowledge and case-based reasoning （CBR） into the computer-aided design is described by combining with the actual characteristic in injection mold design, and the design process of case-based reasoning method is also given. A case library including the information of parting surface is built with the index of main shape features, The automatic design of the mold parting surface is realized combined with the forward-reasoning method and the similarity solution procedure. The rule knowledge library is also founded including the knowledge, principles and experiences for parting surface design. An example is used to show the validity of the method, and the quality and the efficiency of the mold design are improved.
基金financially supported by the Program for New Century Excellent Talents in University(No.NCET-13-0229)the National Science&Technology Key Projects of Numerical Control(No.2012ZX04010-031,2012ZX0412-011)Natural Science Foundation of Hubei Province,China(2011CDB279)
文摘Deformation of casting during the solidification process has puzzled many engineers and scientists for years. In order to attain the goal of near-net forming by casting, numerical simulation is a powerful tool. Traditional methods compute the thermal stress of both the casting and the mold. This method suffers the problem of massive calculation and failure of convergence. This paper proposes an improved Mold Surface Element Method, the main idea of which is to use the surface elements instead of body elements to express the interactions between the casting and the mold. The proposed method shows a high computation efficiency and provides satisfactory precision for engineering. Two practical casting products were used to verify the proposed method. The simulated results agree well with those observed in practical products. The proposed method is believed to benefit production practice and to provide theoretical guidance.
文摘The effects of the wavelength and orientation of machined grooves on a mold surface, casting speed, and melt superheat on the formation of surface marks on as-cast ingots were studied with an immersion casting tester and copper mold chill blocks. The mold surface topographies included a polished smooth surface, and those with machined unidirectional parallel contoured grooves oriented either parallel (vertical) or perpendicular (horizontal) to the casting direction. The unidirectional grooves were 0.232 mm deep with wavelength or spacing between 1 and 15 mm. The casting speed and melt superheat were between 1 and 200 mm/s, and 10 and 50 K, respectively. Two primary types of surface marks were observed on ingots cast with the copper mold with smooth surface topography, namely the finer and closely spaced ripples (Type I), and the widely spaced but coarser laps (Type II). The latter were more prevalent at the higher casting speeds and melt superheats. Qualitatively, formation of both types of surface marks on the as-cast ingots of the aluminum alloy 3003 appeared to be alleviated by increase in casting speed and melt superheat, and by the use of molds with grooved surface topography. In fact, casting with a mold surface with 1 mm spaced grooves that are perpendicular to the casting direction eliminated the formation of surface marks at casting speeds greater than 1 mm/s. It also improved the uniformity of the ingot subsurface microstructure and eliminated the associated subsurface segregation.
文摘The fact that the amount of the mold flux components differs at differentlocations on the cracking surface indicates that the longitudinal surface cracks are initiallyformed in the mold and are enlarged in the secondary cooling zone. Based on the hot ductilitymeasurement of two typical container used steels, it is known that the steels are in severeembrittlement state in the temperature range of 825-775 deg C. By means of increasing Cr/Ni platingthickness on the upper part of the mold, reducing mold heat flux, adopting new secondary coolingpattern, etc., the occurrence of the surface longitudinal cracks on the steel CC (continuouscasting) slabs has been significantly reduced.
