In order to conform to dimensional tolerances, an efficient numerical method, displacement iterative compensation method, based on finite element methodology （FEM） was presented for the wax pattern die profile desig...In order to conform to dimensional tolerances, an efficient numerical method, displacement iterative compensation method, based on finite element methodology （FEM） was presented for the wax pattern die profile design of turbine blades. Casting shrinkages at different positions of the blade which was considered nonlinear thermo-mechanical casting deformations were calculated. Based on the displacement iterative compensation method proposed, the optimized wax pattern die profile can be established. For a A356 alloy blade, substantial reduction in dimensional and shape tolerances was achieved with the developed die shape optimization system. Numerical simulation result obtained by the proposed method shows a good agreement with the result measured experimentally. After four times iterations, compared with the CAD model of turbine blade, the total form error decreases to 0.001 978 mm from the orevious 0.515 815 mm.展开更多
The paper deals with the production technology of knee joint replacement by using rapid prototyping technology.The aim of the work is to outline the manufacturing technology intended for prototype production with the ...The paper deals with the production technology of knee joint replacement by using rapid prototyping technology.The aim of the work is to outline the manufacturing technology intended for prototype production with the use of rapid prototyping and investment casting technology for use in orthopaedics and the surgery of knee joint replacement.The research results should make an effective contribution in the attempts to minimize the invasive surgical procedure,shorten the production of knee joint replacement as well as reduce the cost.At present,the research is focused on the preparation of STL data from CT (Computed Tomography) and verification of the production technology of prototypes made using available RP technology and its evaluation.展开更多
A rapid wax injection tool of a gearbox shift fork was designed, simulated, and manufactured using rapid prototyping and rapid tooling technology to save time and cost of producing wax models used for the investment c...A rapid wax injection tool of a gearbox shift fork was designed, simulated, and manufactured using rapid prototyping and rapid tooling technology to save time and cost of producing wax models used for the investment casting process. CAE simulation softwares, in particular, MoldFlow, are used to get wax injection moulding parameters such as filling parameters, temperature profiles, freeze time, speed, and pressure. The results of this research were compared with conventional wax model production methods. The criteria of such comparison were based upon parameters such as time, cost, and other related characteristics, which resulted in saving of 50% in time and 60% in cost. In this research, design, assembly, and wax injection operation of the wax tool took 10 days. Considering the fact that wax melting temperature is as low as 70℃ and injection pressure of 0.5 MPa, the tool suffers no damage due to the thermal and pressure stresses, leading to the mass production of wax models.展开更多
Selective laser sintering(SLS),as a kind of additive manufacturing technology,which uses a laser beam to scan and heat powder material layer by layer to form parts(models),is widely used in the field of casting,mainly...Selective laser sintering(SLS),as a kind of additive manufacturing technology,which uses a laser beam to scan and heat powder material layer by layer to form parts(models),is widely used in the field of casting,mainly for preparing casting coated sand cores,investment casting patterns,etc.The SLS technique facilitates rapid casting and shortens the casting production periods by eliminating mold preparation.In this study,we reached conclusions for the basic principles and characteristics of SLS methods,and focused on the research status,key technology and development trend of SLS in the fields of forming coated sand-casting molds and investment casting patterns.展开更多
An integrative computer aided investment casting (CAIC) technology for making complicated superalloy castings was described. Key processes of CAIC were discussed including the choice of SLS (Selectively Laser Sinterin...An integrative computer aided investment casting (CAIC) technology for making complicated superalloy castings was described. Key processes of CAIC were discussed including the choice of SLS (Selectively Laser Sintering) materials, sintering parameters, solidification simulation and gating and risering system optimization. Using CAIC process, many large-sized quality superalloy castings with complicated shape and thin wall have been produced successfully and economically in Central Iron & steel Research Institute (CISRI).展开更多
Processing technologies for the mass production of aero and industrial gas turbine engine hot-section components made by the investment casting process are discussed. Howmet Corporation is involved in most of these te...Processing technologies for the mass production of aero and industrial gas turbine engine hot-section components made by the investment casting process are discussed. Howmet Corporation is involved in most of these technologies because of the end-user's desire for a finished part. These technologies include pattern-making (using a variety of wax and plastic materials, rapid prototyping, 'hard' tooling, and wax injection machines), silica-zircon and alumina cores that produce internal passages, shells for very large parts and for use with alloys containing reactive elements, Ni, Co, and Ti alloys that are cleaner than ever before,zirconia, silica, and mullite crucibles;computer-controls,robotics,and the manufacture of vacuum casting furnaces; cleaning and finishing equipment designed to quickly process parts with minimal variation,and post-casting operations including hot isostatic pressing (HIP),heat treating,coating,and machining. These technologies will be discussed along with process capabilities required by today's turbine hot-section component suppliers.展开更多
基金Project (2008ZE53042) supported by National Aerospace Science Foundation of China
文摘In order to conform to dimensional tolerances, an efficient numerical method, displacement iterative compensation method, based on finite element methodology （FEM） was presented for the wax pattern die profile design of turbine blades. Casting shrinkages at different positions of the blade which was considered nonlinear thermo-mechanical casting deformations were calculated. Based on the displacement iterative compensation method proposed, the optimized wax pattern die profile can be established. For a A356 alloy blade, substantial reduction in dimensional and shape tolerances was achieved with the developed die shape optimization system. Numerical simulation result obtained by the proposed method shows a good agreement with the result measured experimentally. After four times iterations, compared with the CAD model of turbine blade, the total form error decreases to 0.001 978 mm from the orevious 0.515 815 mm.
基金supported by the specific research project on "Production Technology of Complex Parts with Specific Requirements on Shape and Function Properties",ID No. 404,Reg. No. FSI-J-10-73,which was funded by FME BUT
文摘The paper deals with the production technology of knee joint replacement by using rapid prototyping technology.The aim of the work is to outline the manufacturing technology intended for prototype production with the use of rapid prototyping and investment casting technology for use in orthopaedics and the surgery of knee joint replacement.The research results should make an effective contribution in the attempts to minimize the invasive surgical procedure,shorten the production of knee joint replacement as well as reduce the cost.At present,the research is focused on the preparation of STL data from CT (Computed Tomography) and verification of the production technology of prototypes made using available RP technology and its evaluation.
基金the Rapid Prototyping & Tool-ing Branch of SAPCO Part Supplier of Car Manufacturing Co. of Iran-Khodro and POULADIR Investment Casting Company for supporting this project
文摘A rapid wax injection tool of a gearbox shift fork was designed, simulated, and manufactured using rapid prototyping and rapid tooling technology to save time and cost of producing wax models used for the investment casting process. CAE simulation softwares, in particular, MoldFlow, are used to get wax injection moulding parameters such as filling parameters, temperature profiles, freeze time, speed, and pressure. The results of this research were compared with conventional wax model production methods. The criteria of such comparison were based upon parameters such as time, cost, and other related characteristics, which resulted in saving of 50% in time and 60% in cost. In this research, design, assembly, and wax injection operation of the wax tool took 10 days. Considering the fact that wax melting temperature is as low as 70℃ and injection pressure of 0.5 MPa, the tool suffers no damage due to the thermal and pressure stresses, leading to the mass production of wax models.
基金supported by the National Key R&D Program of China(2020YFB2008300,2020YFB2008304)the National Natural Science Foundation of China(51775204,51375190,59635040)。
文摘Selective laser sintering(SLS),as a kind of additive manufacturing technology,which uses a laser beam to scan and heat powder material layer by layer to form parts(models),is widely used in the field of casting,mainly for preparing casting coated sand cores,investment casting patterns,etc.The SLS technique facilitates rapid casting and shortens the casting production periods by eliminating mold preparation.In this study,we reached conclusions for the basic principles and characteristics of SLS methods,and focused on the research status,key technology and development trend of SLS in the fields of forming coated sand-casting molds and investment casting patterns.
文摘An integrative computer aided investment casting (CAIC) technology for making complicated superalloy castings was described. Key processes of CAIC were discussed including the choice of SLS (Selectively Laser Sintering) materials, sintering parameters, solidification simulation and gating and risering system optimization. Using CAIC process, many large-sized quality superalloy castings with complicated shape and thin wall have been produced successfully and economically in Central Iron & steel Research Institute (CISRI).
文摘Processing technologies for the mass production of aero and industrial gas turbine engine hot-section components made by the investment casting process are discussed. Howmet Corporation is involved in most of these technologies because of the end-user's desire for a finished part. These technologies include pattern-making (using a variety of wax and plastic materials, rapid prototyping, 'hard' tooling, and wax injection machines), silica-zircon and alumina cores that produce internal passages, shells for very large parts and for use with alloys containing reactive elements, Ni, Co, and Ti alloys that are cleaner than ever before,zirconia, silica, and mullite crucibles;computer-controls,robotics,and the manufacture of vacuum casting furnaces; cleaning and finishing equipment designed to quickly process parts with minimal variation,and post-casting operations including hot isostatic pressing (HIP),heat treating,coating,and machining. These technologies will be discussed along with process capabilities required by today's turbine hot-section component suppliers.
