The final quality of complex conical-section rings depends on co-design of multiple processes in forming process chain.In this study,for a complex aeroengine casing ring with a large slope and a flange on its end,a co...The final quality of complex conical-section rings depends on co-design of multiple processes in forming process chain.In this study,for a complex aeroengine casing ring with a large slope and a flange on its end,a co-design method of the forming process chain is put forward towards the objective of precision forming,which not only proposes a standard process route composed of multiple processes of upsetting,punching,rectangular ring rolling,loose tooling forging and profiled ring rolling,but also presents co-design methods of dies and blanks for all the processes.For profiled ring rolling,a design method of preformed blank that makes the blank and the target conical-section ring have the same axial volume distribution is proposed.By the method,the axial metal redistribution during the process can be alleviated greatly thus improving the forming stability and precision of the ring.Based on the geometric features of designed preformed blank,design methods of blanks and dies for loose tolling forging,rectangular ring rolling,punching and upsetting are proposed sequentially.In view of the key roles of loose tooling forging(manufacturing the preformed blank)and profiled ring rolling on the final quality of the conical ring parts,inherited FE simulations for these two processes are performed to verify the proposed design methods and determine appropriate design parameter.It is demonstrated that the proposed design method has significant advantages in improving forming precision.Besides,a suggestive value 1.5 of the rolling ratio for profiled ring rolling(a key design parameter)is given based on comprehensive consideration of multiple indicators such as ring roundness,deformation uniformity and forming load.The corresponding industrial experiments performed illustrate that a high forming precision of the conical-section aeroengine casing ring is achieved.展开更多
An outer ring of 29320 self-aliging roller bearing was used in an experimental study on the casting of Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(22.5) amorphous alloy.Numerical simulations of mold filling and solidification p...An outer ring of 29320 self-aliging roller bearing was used in an experimental study on the casting of Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(22.5) amorphous alloy.Numerical simulations of mold filling and solidification processes were carried out to determine the velocity fields and temperature fields of the alloy melt during mold filling process as well as the temperature fields and temperature gradient fields in the course of the solidification.According to the results,a cast with a complete shape can be obtained at 1200℃under the condition that the cooling rate is greater than the critical cooling rate.The ring-shaped part with a thickness of 25 mm,an equivalent diameter of 22 mm,and a mass of 1.32 kg was prepared by gravity casting in a copper mold.X-ray diffraction and differential scanning calorimetry data revealed that the produced cast had the amorphous structure.展开更多
Cylindrical rings with thin wall and high web ribs(CRTWHWR)are widely used as the key load bearing structures such as rocket body and space station cabin in aerospace field.However,it is still difficult to efficiently...Cylindrical rings with thin wall and high web ribs(CRTWHWR)are widely used as the key load bearing structures such as rocket body and space station cabin in aerospace field.However,it is still difficult to efficiently manufacture CRTWHWR with high performance because of their extreme geometry with thin-walled skins,high web ribs and large size.In this paper,a novel radial envelope forming process is put forward to efficiently achieve the plastic forming of CRTWHWR with high performance.Firstly,the principle of radial envelope forming process is clarified.Then,an efficient design method for the tool motion and geometry is proposed based on the reverse envelope principle,i.e.,CRTWHWR is adopted to reversely envelope the tool and thus the tool which does not interfere with CRTWHWR can be efficiently obtained in a single operation.Finally,a reasonable 3D FE model of the radial envelope forming process of CRTWHWR is established and the radial envelope forming mechanism of CRTWHWR is comprehensively revealed.Through the FE simulation and experiments with material of plastic mud,a typical CRTWHWR with diameter of 300 mm,axial height of 192 mm,the maximum rib height of 25 mm,the minimum rib thickness of 3 mm and skin thickness of 5 mm is radial envelope formed,i.e.,the ratio of the maximum rib height to the minimum rib thickness reaches 8.33,the ratio of the maximum rib height to skin thickness reaches 5 and the ratio of diameter to the minimum rib thickness reaches 100.The above results verify that the proposed radial envelope forming process has great potentials in efficiently manufacturing CRTWHWR with extreme geometry.展开更多
基金the National Natural Science Foundation of China(52275378).
文摘The final quality of complex conical-section rings depends on co-design of multiple processes in forming process chain.In this study,for a complex aeroengine casing ring with a large slope and a flange on its end,a co-design method of the forming process chain is put forward towards the objective of precision forming,which not only proposes a standard process route composed of multiple processes of upsetting,punching,rectangular ring rolling,loose tooling forging and profiled ring rolling,but also presents co-design methods of dies and blanks for all the processes.For profiled ring rolling,a design method of preformed blank that makes the blank and the target conical-section ring have the same axial volume distribution is proposed.By the method,the axial metal redistribution during the process can be alleviated greatly thus improving the forming stability and precision of the ring.Based on the geometric features of designed preformed blank,design methods of blanks and dies for loose tolling forging,rectangular ring rolling,punching and upsetting are proposed sequentially.In view of the key roles of loose tooling forging(manufacturing the preformed blank)and profiled ring rolling on the final quality of the conical ring parts,inherited FE simulations for these two processes are performed to verify the proposed design methods and determine appropriate design parameter.It is demonstrated that the proposed design method has significant advantages in improving forming precision.Besides,a suggestive value 1.5 of the rolling ratio for profiled ring rolling(a key design parameter)is given based on comprehensive consideration of multiple indicators such as ring roundness,deformation uniformity and forming load.The corresponding industrial experiments performed illustrate that a high forming precision of the conical-section aeroengine casing ring is achieved.
基金the National Natural Science Foundation of China(Nos.52071278,51827801)the National Key Research and Development Program of China(No.2018YFA0703603)the Hebei Normal University of Science&Technology,China(No.2021YB012).
文摘An outer ring of 29320 self-aliging roller bearing was used in an experimental study on the casting of Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(22.5) amorphous alloy.Numerical simulations of mold filling and solidification processes were carried out to determine the velocity fields and temperature fields of the alloy melt during mold filling process as well as the temperature fields and temperature gradient fields in the course of the solidification.According to the results,a cast with a complete shape can be obtained at 1200℃under the condition that the cooling rate is greater than the critical cooling rate.The ring-shaped part with a thickness of 25 mm,an equivalent diameter of 22 mm,and a mass of 1.32 kg was prepared by gravity casting in a copper mold.X-ray diffraction and differential scanning calorimetry data revealed that the produced cast had the amorphous structure.
基金the National Natural Science Foundation of China(No.U2037204)the 111 Project(B17034)+1 种基金Innovative Research Team Development Program of Ministry of Education of China(No.IRT17R83)the National Natural Science Foundation of China(No.52005375)for the support given to this research。
文摘Cylindrical rings with thin wall and high web ribs(CRTWHWR)are widely used as the key load bearing structures such as rocket body and space station cabin in aerospace field.However,it is still difficult to efficiently manufacture CRTWHWR with high performance because of their extreme geometry with thin-walled skins,high web ribs and large size.In this paper,a novel radial envelope forming process is put forward to efficiently achieve the plastic forming of CRTWHWR with high performance.Firstly,the principle of radial envelope forming process is clarified.Then,an efficient design method for the tool motion and geometry is proposed based on the reverse envelope principle,i.e.,CRTWHWR is adopted to reversely envelope the tool and thus the tool which does not interfere with CRTWHWR can be efficiently obtained in a single operation.Finally,a reasonable 3D FE model of the radial envelope forming process of CRTWHWR is established and the radial envelope forming mechanism of CRTWHWR is comprehensively revealed.Through the FE simulation and experiments with material of plastic mud,a typical CRTWHWR with diameter of 300 mm,axial height of 192 mm,the maximum rib height of 25 mm,the minimum rib thickness of 3 mm and skin thickness of 5 mm is radial envelope formed,i.e.,the ratio of the maximum rib height to the minimum rib thickness reaches 8.33,the ratio of the maximum rib height to skin thickness reaches 5 and the ratio of diameter to the minimum rib thickness reaches 100.The above results verify that the proposed radial envelope forming process has great potentials in efficiently manufacturing CRTWHWR with extreme geometry.
