Constrained groove pressing(CGP)is a severe plastic deformation(SPD)technique used as a strengthening method for sheet metal.In the current work,an optimal/cost-saving design for CGP dies was attained using the stress...Constrained groove pressing(CGP)is a severe plastic deformation(SPD)technique used as a strengthening method for sheet metal.In the current work,an optimal/cost-saving design for CGP dies was attained using the stress analysis tool in SolidWorks Simulation Xpress wizard.This study examined low-cost and widely industrially applied aluminium materials,i.e.,pure 1050 Al and 5052 Al alloy.Each material was subjected to three passes of the CGP process using a 150 tons capacity press.For both materials,inter-pass annealing treatment was undertaken before the third pass.The effect of the number of CGP passes on the microstructure and tensile properties was studied after each pass.For CGPed pure 1050 Al with respect to the as-received material,the ultimate tensile strength(UTS),yield strength(YS)and YS/UTS ratio increased with an increasing number of CGP passes until the second pass,while elongation decreased with the number of passes.For CGPed 5052 Al alloy,the UTS and YS increased after the first pass and then decreased after the second pass.Variations in the elongation and YS/UTS ratio of 5052 Al alloy after the CGP process were insignificant.After inter-pass annealing and applying the third CGP pass,the strength of pure 1050 Al decreased,and that of 5052 Al alloy increased,which was attributed to the influence of composition on their structures.The strength-ductility balance decreased with an increasing number of CGP passes in both materials.展开更多
The use of aluminum, particularly for engine blocks, has grown considerably in the past ten years, and continues to rise in the automotive industry. In order to enhance the quality and engineering functionality of die...The use of aluminum, particularly for engine blocks, has grown considerably in the past ten years, and continues to rise in the automotive industry. In order to enhance the quality and engineering functionality of die cast engine blocks, die design and processes have to be optimized. In this study, a computer simulation software, MAGMAsoft, as an advanced tool for optimizing die design and casting process, was employed to virtually visualize cavity filling and patterns of a V6 engine block. The original die design and process was simulated first to establish a baseline. A reality check was used to verify the predicted results. Then, the die modification with a different runner system was made by using a CAD software, Unigraphics (UG). The simulation on combinations of the modified die design and revised process was performed to examine the effect of die modification and process change on flow filling of V6 engine blocks. The simulated prediction indicates that the enhancement of cavity filling due to the die and process modification minimizes the occurrence of defects during casting, and consequently improves the quality of blocks. The results of mechanical testing show a significant increase in fatigue strengths, and a moderately improvement on tensile properties for the blocks die cast with the new die design and process in comparison with those produced by the original ones.展开更多
Logic components are used to support the conceptual design Taking the stamping die structure as the research object,several logic components are defined for the conceptual die construction design A new method log...Logic components are used to support the conceptual design Taking the stamping die structure as the research object,several logic components are defined for the conceptual die construction design A new method logic assembly modeling is presented to satisfy the characteristic of the top down die design process Representing shapes and spatial relations in logic can provide a natural,intuitive method of developing complete computer systems for reasoning about die construction design at the conceptual stage This method can reflect the designer's thought clearly and provide the designer with a test bed for generating alternatives and performing reasoning work at the conceptual die design stage展开更多
The finite element analysis (FEA) software Ansys was employed to study the stress state of the dies of both plane and non-plane parting face structures with uniform interference and the die of plane parting face struc...The finite element analysis (FEA) software Ansys was employed to study the stress state of the dies of both plane and non-plane parting face structures with uniform interference and the die of plane parting face structure with non-uniform interference. Considering the symmetry of the die, a half gear tooth model of the two-ring assembled die with 2.5 GPa inner pressure was constructed. Four paths were defined to investigate the stress state at the bottom corner of the die where stress concentration was serious. FEA results show that the change of parting face from non-plane to plane can greatly reduce the stress at the teeth tips of the die so that the tip fracture is avoided. The interference structure of the die is the most important influencing factor for the stress concentration at the bottom corner. When non-uniform interference is adopted the first principal stress at the corner on the defined paths of the die is much lower than that with uniform interference. The bottom hole radius is another important influencing factor for the corner stress concentration. The first principal stress at the corner of the plane parting face die with non-uniform interference is reduced from 2.3 to 1.9 GPa when the hole radius increases from 12.5 to 16.0 mm. The optimization of the die structure increases the life of the die from 100 to 6 000 hits.展开更多
Many disadvantages exist in the traditional die design method which belongs to serial pattern. It is well known that heat treatment is highly important to the dies. A new idea of concurrent design for heat treatment p...Many disadvantages exist in the traditional die design method which belongs to serial pattern. It is well known that heat treatment is highly important to the dies. A new idea of concurrent design for heat treatment process of die and mould was developed in order to overcome the existent shortcomings of heat treatment process. Heat treatment CAD/CAE was integrated with concurrent circumstance and the relevant model was built. These investigations can remarkably improve efficiency, reduce cost and ensure quality of R and D for products.展开更多
In the extrusion of shapes with flat faced die,the proper design of die land is of critical importance in avoiding the generations of geometry defects.A methodology for the design of die land,which consists of a simu...In the extrusion of shapes with flat faced die,the proper design of die land is of critical importance in avoiding the generations of geometry defects.A methodology for the design of die land,which consists of a simulation adjustment iteration,is proposed.The metal flow in extrusion is simulated by the three dimensional finite element method and the die land is adjusted according to the simulation result.Both the formulae for adjustment of the die land and the criterion for the judgment of proper die land are suggested.The extrusion of an L section shape is chosen as the computational example and the result is compared with the industrial design.展开更多
Die casting process is one of the prime options for m anufacturing precisely dimensioned, sharply defined metal parts. The design of d ie casting dies comprises several stages and entails a large amount of time. Tra d...Die casting process is one of the prime options for m anufacturing precisely dimensioned, sharply defined metal parts. The design of d ie casting dies comprises several stages and entails a large amount of time. Tra ditionally, the different stages of the die design were not integrated but exist as separate entities. Moreover, recurring modifications or even redesigns are r equired due to the complexity in achieving an accurate initial die design. As a result, die design is usually time-consuming and costly with respect to resourc es. The die casting industry will greatly benefit if proper application software are developed that integrates the different die design stages and allows editin g of die design as and when needed. Hence it is imperative to create an integrat ed die design system that shortens the die design time. This paper presents a research that establishes a prototype of an integrated die design system. It is developed using the commercial SolidWorks CAD system and n amed DiWorks. The aim of building the system on a commercial CAD system is to ut ilise the resources and features of the CAD system to speed up the die design pr ocess. DiWorks consists of six distinct modules: Project Manager, Cavity Insert Builder, Gating System Constructor, Die Base Designer, Ejector System Constructo r and Standard Components Library. Through these six modules, the die designer c an create a complete die casting die beginning from a product part model. It is a user-friendly system that allows both experienced and novice die designers to easily accomplish the task of die design. The practical goal of this research is twofold: to develop a system that integra tes the die design process and at the same time facilitates the editing of d ie design during or after the course of the design process. The research approac h includes (i) parametric design, (ii) feature-based design (iii) system modeli ng and implementation. Parametric design deals with variable dimensions as contr ol parameters, and it is an efficient tool for creating models based on paramete rs. Parametric design not only increases the design efficiency, but also makes t he updates and modifications of existing designs easier and faster, since these can be achieved by changing the parameters of the parametric model. Feature-bas ed design is used to design a product with features that are functionally define d by attributes and are geometrically represented by a set of parameters. The re sults of this research will aid the automation of the die design process, thus i mproving the efficiency and quality of, and reducing the cost of die design.展开更多
Larger and larger proportions of aluminium castings,especially those produced by the die casting process,can be observed during recent years in the automotive industry,house-hold articles and others.In case of the aut...Larger and larger proportions of aluminium castings,especially those produced by the die casting process,can be observed during recent years in the automotive industry,house-hold articles and others.In case of the automotive industry,apart from the traditional elements produced by the die pressure method such as engine blocks or crank shaft bedplates,aluminium is displacing steel from structural parts of cars('body in white').The current state and development directions of the structural solutions of cold-chamber die castings are analysed in this paper.These solutions drive the prospective development of these machines and die casting technology.The focus is mainly on essential functional systems such as:hydraulic drives of closing and locking units,as well as pressing in die machines of known companies present on the European market.展开更多
The maximum internal tangential stress is a critical parameter for the design of the PDC （polycrystalline diamond compact） die that has been widely applied to offshore oil drilling. A new simple equation for the cal...The maximum internal tangential stress is a critical parameter for the design of the PDC （polycrystalline diamond compact） die that has been widely applied to offshore oil drilling. A new simple equation for the calculation of the stress is developed, and verified by the test data from Kingdream Corp. of China, the largest bit Company in China. An opti- mum method for the design of the PDC die is presented and demonstrated in detail, and software for the design and FEM analysis of the die is developed on the basis of the method. This software has been used in oil industry in recent years.展开更多
文摘Constrained groove pressing(CGP)is a severe plastic deformation(SPD)technique used as a strengthening method for sheet metal.In the current work,an optimal/cost-saving design for CGP dies was attained using the stress analysis tool in SolidWorks Simulation Xpress wizard.This study examined low-cost and widely industrially applied aluminium materials,i.e.,pure 1050 Al and 5052 Al alloy.Each material was subjected to three passes of the CGP process using a 150 tons capacity press.For both materials,inter-pass annealing treatment was undertaken before the third pass.The effect of the number of CGP passes on the microstructure and tensile properties was studied after each pass.For CGPed pure 1050 Al with respect to the as-received material,the ultimate tensile strength(UTS),yield strength(YS)and YS/UTS ratio increased with an increasing number of CGP passes until the second pass,while elongation decreased with the number of passes.For CGPed 5052 Al alloy,the UTS and YS increased after the first pass and then decreased after the second pass.Variations in the elongation and YS/UTS ratio of 5052 Al alloy after the CGP process were insignificant.After inter-pass annealing and applying the third CGP pass,the strength of pure 1050 Al decreased,and that of 5052 Al alloy increased,which was attributed to the influence of composition on their structures.The strength-ductility balance decreased with an increasing number of CGP passes in both materials.
文摘The use of aluminum, particularly for engine blocks, has grown considerably in the past ten years, and continues to rise in the automotive industry. In order to enhance the quality and engineering functionality of die cast engine blocks, die design and processes have to be optimized. In this study, a computer simulation software, MAGMAsoft, as an advanced tool for optimizing die design and casting process, was employed to virtually visualize cavity filling and patterns of a V6 engine block. The original die design and process was simulated first to establish a baseline. A reality check was used to verify the predicted results. Then, the die modification with a different runner system was made by using a CAD software, Unigraphics (UG). The simulation on combinations of the modified die design and revised process was performed to examine the effect of die modification and process change on flow filling of V6 engine blocks. The simulated prediction indicates that the enhancement of cavity filling due to the die and process modification minimizes the occurrence of defects during casting, and consequently improves the quality of blocks. The results of mechanical testing show a significant increase in fatigue strengths, and a moderately improvement on tensile properties for the blocks die cast with the new die design and process in comparison with those produced by the original ones.
文摘Logic components are used to support the conceptual design Taking the stamping die structure as the research object,several logic components are defined for the conceptual die construction design A new method logic assembly modeling is presented to satisfy the characteristic of the top down die design process Representing shapes and spatial relations in logic can provide a natural,intuitive method of developing complete computer systems for reasoning about die construction design at the conceptual stage This method can reflect the designer's thought clearly and provide the designer with a test bed for generating alternatives and performing reasoning work at the conceptual die design stage
基金Project(2006BAF04B06) supported by the National Key Technology R & D Program of ChinaProject(2005AA101B19) supported by the Key Technology R & D Program of Hubei Province, China
文摘The finite element analysis (FEA) software Ansys was employed to study the stress state of the dies of both plane and non-plane parting face structures with uniform interference and the die of plane parting face structure with non-uniform interference. Considering the symmetry of the die, a half gear tooth model of the two-ring assembled die with 2.5 GPa inner pressure was constructed. Four paths were defined to investigate the stress state at the bottom corner of the die where stress concentration was serious. FEA results show that the change of parting face from non-plane to plane can greatly reduce the stress at the teeth tips of the die so that the tip fracture is avoided. The interference structure of the die is the most important influencing factor for the stress concentration at the bottom corner. When non-uniform interference is adopted the first principal stress at the corner on the defined paths of the die is much lower than that with uniform interference. The bottom hole radius is another important influencing factor for the corner stress concentration. The first principal stress at the corner of the plane parting face die with non-uniform interference is reduced from 2.3 to 1.9 GPa when the hole radius increases from 12.5 to 16.0 mm. The optimization of the die structure increases the life of the die from 100 to 6 000 hits.
基金ItemSponsored by National Natural Science Foundation of China (50075053) Science and Technology Foundation ofShanghai Higher Education (03 HZ01)
文摘Many disadvantages exist in the traditional die design method which belongs to serial pattern. It is well known that heat treatment is highly important to the dies. A new idea of concurrent design for heat treatment process of die and mould was developed in order to overcome the existent shortcomings of heat treatment process. Heat treatment CAD/CAE was integrated with concurrent circumstance and the relevant model was built. These investigations can remarkably improve efficiency, reduce cost and ensure quality of R and D for products.
文摘In the extrusion of shapes with flat faced die,the proper design of die land is of critical importance in avoiding the generations of geometry defects.A methodology for the design of die land,which consists of a simulation adjustment iteration,is proposed.The metal flow in extrusion is simulated by the three dimensional finite element method and the die land is adjusted according to the simulation result.Both the formulae for adjustment of the die land and the criterion for the judgment of proper die land are suggested.The extrusion of an L section shape is chosen as the computational example and the result is compared with the industrial design.
文摘Die casting process is one of the prime options for m anufacturing precisely dimensioned, sharply defined metal parts. The design of d ie casting dies comprises several stages and entails a large amount of time. Tra ditionally, the different stages of the die design were not integrated but exist as separate entities. Moreover, recurring modifications or even redesigns are r equired due to the complexity in achieving an accurate initial die design. As a result, die design is usually time-consuming and costly with respect to resourc es. The die casting industry will greatly benefit if proper application software are developed that integrates the different die design stages and allows editin g of die design as and when needed. Hence it is imperative to create an integrat ed die design system that shortens the die design time. This paper presents a research that establishes a prototype of an integrated die design system. It is developed using the commercial SolidWorks CAD system and n amed DiWorks. The aim of building the system on a commercial CAD system is to ut ilise the resources and features of the CAD system to speed up the die design pr ocess. DiWorks consists of six distinct modules: Project Manager, Cavity Insert Builder, Gating System Constructor, Die Base Designer, Ejector System Constructo r and Standard Components Library. Through these six modules, the die designer c an create a complete die casting die beginning from a product part model. It is a user-friendly system that allows both experienced and novice die designers to easily accomplish the task of die design. The practical goal of this research is twofold: to develop a system that integra tes the die design process and at the same time facilitates the editing of d ie design during or after the course of the design process. The research approac h includes (i) parametric design, (ii) feature-based design (iii) system modeli ng and implementation. Parametric design deals with variable dimensions as contr ol parameters, and it is an efficient tool for creating models based on paramete rs. Parametric design not only increases the design efficiency, but also makes t he updates and modifications of existing designs easier and faster, since these can be achieved by changing the parameters of the parametric model. Feature-bas ed design is used to design a product with features that are functionally define d by attributes and are geometrically represented by a set of parameters. The re sults of this research will aid the automation of the die design process, thus i mproving the efficiency and quality of, and reducing the cost of die design.
文摘Larger and larger proportions of aluminium castings,especially those produced by the die casting process,can be observed during recent years in the automotive industry,house-hold articles and others.In case of the automotive industry,apart from the traditional elements produced by the die pressure method such as engine blocks or crank shaft bedplates,aluminium is displacing steel from structural parts of cars('body in white').The current state and development directions of the structural solutions of cold-chamber die castings are analysed in this paper.These solutions drive the prospective development of these machines and die casting technology.The focus is mainly on essential functional systems such as:hydraulic drives of closing and locking units,as well as pressing in die machines of known companies present on the European market.
文摘The maximum internal tangential stress is a critical parameter for the design of the PDC （polycrystalline diamond compact） die that has been widely applied to offshore oil drilling. A new simple equation for the calculation of the stress is developed, and verified by the test data from Kingdream Corp. of China, the largest bit Company in China. An opti- mum method for the design of the PDC die is presented and demonstrated in detail, and software for the design and FEM analysis of the die is developed on the basis of the method. This software has been used in oil industry in recent years.
