Deformation behavior and microstructure of AlMg6Mn alloy subjected to shear spinning were studied by means of mechanical characterization, optical and SEM+EDS microscopy. Specimens were shear spun on an industrial sp...Deformation behavior and microstructure of AlMg6Mn alloy subjected to shear spinning were studied by means of mechanical characterization, optical and SEM+EDS microscopy. Specimens were shear spun on an industrial spinning machine using different mandrels, providing reductions of wall thickness of 30%, 50% and 68%. The grain structure developed during shear spinning refines gradually. The grains elongate in axial direction with increase of reduction, and also stretches along circumferencial direction. Optimal combination of strength and elongation is observed. This is attributed to grain refinement and dislocation reactions with particles and atoms of Mg and Mn in solid solution.展开更多
In this paper, the 3D elastic-plastic simulation was carried out by using finite element (FE) code according to the phenomena of flange keeping straight, bending towards headstock and bending towards tailstock in th...In this paper, the 3D elastic-plastic simulation was carried out by using finite element (FE) code according to the phenomena of flange keeping straight, bending towards headstock and bending towards tailstock in the shear spinning experiments for TC4 alloy. The simulation results for the three kinds of deformations of the flange agree well with the experimental results. So it is possible to explain the reason of flange bending by analyzing the strain vectors in the flange for the three kinds of deformation, which shows that it is important to apply the FE simulation technology for predicting the defects and optimizing the spinning process of TC4 alloys.展开更多
The quenching-spinning(Q-S)process,i.e.,shear spinning after blank quenching,has been increasingly utilized to form 2219 aluminum alloy complex thin-walled components.However,the changes in material property,shape and...The quenching-spinning(Q-S)process,i.e.,shear spinning after blank quenching,has been increasingly utilized to form 2219 aluminum alloy complex thin-walled components.However,the changes in material property,shape and stress of the blanks after quenching will affect the spin-ning forming precision.In this study,the rules and mechanisms of these effects are investigated based on a combined finite element(FE)model including blank quenching and component spinning process.The results indicate that the increase of material strength and the existence of distortion of the quenched blank lead to a notable increase in the non-uniformity of the circumferential compres-sive stress in the spinning area and the increase of the flange swing height during spinning.These changes result in an increase in the wall thickness and component-mandrel gap of the components.The quenching residual stress has little effect on wall thickness and roundness but can noticeably reduce the component-mandrel gap.This is because that the existence of quenching residual stress of the blank can lead to the decrease of the maximum circumferential compressive stress of the workpiece in spinning and an obvious drop in the maximum compressive stress after reaching the stress peak.Quenching distortion is the main factor affecting the roundness.Moreover,the opti-mized installation way of the blank for spinning is obtained.展开更多
Rotationally symmetric workpieces of Ti_(2)AlNb-based alloys have great potential for high-temperature service condition in aviation industry,while the poor workability limits their application until now.In this study...Rotationally symmetric workpieces of Ti_(2)AlNb-based alloys have great potential for high-temperature service condition in aviation industry,while the poor workability limits their application until now.In this study,shear spinning and heat treatment were first conducted to investigate the corresponding microstructure evolution and mechanical properties of Ti_(2)AlNb conical workpieces.The microstructure of the 1^(st) and 2^(nd) pass spun workpieces(SP1 and SP2)mainly consisted of B2+retainedα2phases.After two passes spinning,the B2 phase texture changed from<111>//ND of as-received alloy to be<001>//ND.The ultimate tensile stress(UTS)of SP1 and SP2 was increased to 1163 MPa and 932 MPa,respectively,compared with 782 MPa of as-received alloy at 650℃.Also,the yield stress anomaly(YSA)occurred in SP1 and SP2 because{110}<111>and{112}<111>cross slip systems of B2 phase were difficult to slip at or below room temperature(RT),but they became active at 650℃ and above.As an essential step for increasing the spinnability of multi-pass spinning process of the Ti_(2)AlNb alloy,the H3heat treatment scheme,i.e.960℃/2 h+850℃/12 h,was carried out between two successive passes to increase the hot workability,by which the ductility of the heat treated as-spun workpieces with the microstructure of B2+primary O+acicular secondary O+high amount spheroidizedα2phases reached 72.1%at 900℃.After being subject to the H1 heat treatment scheme,i.e.960℃-2 h,the spun workpieces with the microstructure of B2+primary O+intergranular primaryα2phases achieved an optimized comprehensive mechanical properties both at room temperature and 650℃,which should be chosen as the post-spinning heat treatment process for the service requirement.展开更多
Hot shear spinning experiments with Mg–3.0 Al–1.0 Zn–0.5 Mn(AZ31 B, wt%) magnesium alloy sheets were conducted at various temperatures, spindle speeds and feed ratios to investigate the effects of these processing ...Hot shear spinning experiments with Mg–3.0 Al–1.0 Zn–0.5 Mn(AZ31 B, wt%) magnesium alloy sheets were conducted at various temperatures, spindle speeds and feed ratios to investigate the effects of these processing parameters on the microstructure, crystallographic texture and mechanical properties. The AZ31 B sheet displayed good shear formability at temperatures from 473 to 673 K, spindle speeds from 300 to 600 rev/min and feed ratios from 0.1 to 0.5 mm/rev. During the dynamic recrystallization process, the grain size and texture were affected by the deformation temperature of the hot shear spinning process. Each of the spun sheets presented a strong basal texture, and the c-axis of most of the grains was parallel to the normal direction. The optimal hot shear spinning parameters were determined to be a temperature of 473 K, a spindle speed of 300 rev/min and a feed ratio of 0.1 mm/rev. The yield strength, ultimate tensile strength and elongation in the rolled direction reached 221 MPa, 288 MPa and 14.1%, and those in the transverse direction reached 205 MPa, 280 MPa and 12.4%, respectively. The improved strength and decreased mechanical anisotropy resulted from the fine grain size and strong basal texture.展开更多
文摘Deformation behavior and microstructure of AlMg6Mn alloy subjected to shear spinning were studied by means of mechanical characterization, optical and SEM+EDS microscopy. Specimens were shear spun on an industrial spinning machine using different mandrels, providing reductions of wall thickness of 30%, 50% and 68%. The grain structure developed during shear spinning refines gradually. The grains elongate in axial direction with increase of reduction, and also stretches along circumferencial direction. Optimal combination of strength and elongation is observed. This is attributed to grain refinement and dislocation reactions with particles and atoms of Mg and Mn in solid solution.
文摘In this paper, the 3D elastic-plastic simulation was carried out by using finite element (FE) code according to the phenomena of flange keeping straight, bending towards headstock and bending towards tailstock in the shear spinning experiments for TC4 alloy. The simulation results for the three kinds of deformations of the flange agree well with the experimental results. So it is possible to explain the reason of flange bending by analyzing the strain vectors in the flange for the three kinds of deformation, which shows that it is important to apply the FE simulation technology for predicting the defects and optimizing the spinning process of TC4 alloys.
基金co-supported by the Young Scientists Fund of the National Natural Science Foundation of China(No.52105417)the Foundation of Civil Aviation Flight University of China(Nos.J2022-067,ZJ2022-003 and JG2022-27)the National Science Fund for Excellent Young Scholars of China(No.52122509).
文摘The quenching-spinning(Q-S)process,i.e.,shear spinning after blank quenching,has been increasingly utilized to form 2219 aluminum alloy complex thin-walled components.However,the changes in material property,shape and stress of the blanks after quenching will affect the spin-ning forming precision.In this study,the rules and mechanisms of these effects are investigated based on a combined finite element(FE)model including blank quenching and component spinning process.The results indicate that the increase of material strength and the existence of distortion of the quenched blank lead to a notable increase in the non-uniformity of the circumferential compres-sive stress in the spinning area and the increase of the flange swing height during spinning.These changes result in an increase in the wall thickness and component-mandrel gap of the components.The quenching residual stress has little effect on wall thickness and roundness but can noticeably reduce the component-mandrel gap.This is because that the existence of quenching residual stress of the blank can lead to the decrease of the maximum circumferential compressive stress of the workpiece in spinning and an obvious drop in the maximum compressive stress after reaching the stress peak.Quenching distortion is the main factor affecting the roundness.Moreover,the opti-mized installation way of the blank for spinning is obtained.
基金financially supported by the National Natural Science Foundation of China (No. 51775137)。
文摘Rotationally symmetric workpieces of Ti_(2)AlNb-based alloys have great potential for high-temperature service condition in aviation industry,while the poor workability limits their application until now.In this study,shear spinning and heat treatment were first conducted to investigate the corresponding microstructure evolution and mechanical properties of Ti_(2)AlNb conical workpieces.The microstructure of the 1^(st) and 2^(nd) pass spun workpieces(SP1 and SP2)mainly consisted of B2+retainedα2phases.After two passes spinning,the B2 phase texture changed from<111>//ND of as-received alloy to be<001>//ND.The ultimate tensile stress(UTS)of SP1 and SP2 was increased to 1163 MPa and 932 MPa,respectively,compared with 782 MPa of as-received alloy at 650℃.Also,the yield stress anomaly(YSA)occurred in SP1 and SP2 because{110}<111>and{112}<111>cross slip systems of B2 phase were difficult to slip at or below room temperature(RT),but they became active at 650℃ and above.As an essential step for increasing the spinnability of multi-pass spinning process of the Ti_(2)AlNb alloy,the H3heat treatment scheme,i.e.960℃/2 h+850℃/12 h,was carried out between two successive passes to increase the hot workability,by which the ductility of the heat treated as-spun workpieces with the microstructure of B2+primary O+acicular secondary O+high amount spheroidizedα2phases reached 72.1%at 900℃.After being subject to the H1 heat treatment scheme,i.e.960℃-2 h,the spun workpieces with the microstructure of B2+primary O+intergranular primaryα2phases achieved an optimized comprehensive mechanical properties both at room temperature and 650℃,which should be chosen as the post-spinning heat treatment process for the service requirement.
基金the National Natural Science Foundation of China(Nos.51601112,51701117)the Shanghai Rising-Star Program(No.17QB1403000)。
文摘Hot shear spinning experiments with Mg–3.0 Al–1.0 Zn–0.5 Mn(AZ31 B, wt%) magnesium alloy sheets were conducted at various temperatures, spindle speeds and feed ratios to investigate the effects of these processing parameters on the microstructure, crystallographic texture and mechanical properties. The AZ31 B sheet displayed good shear formability at temperatures from 473 to 673 K, spindle speeds from 300 to 600 rev/min and feed ratios from 0.1 to 0.5 mm/rev. During the dynamic recrystallization process, the grain size and texture were affected by the deformation temperature of the hot shear spinning process. Each of the spun sheets presented a strong basal texture, and the c-axis of most of the grains was parallel to the normal direction. The optimal hot shear spinning parameters were determined to be a temperature of 473 K, a spindle speed of 300 rev/min and a feed ratio of 0.1 mm/rev. The yield strength, ultimate tensile strength and elongation in the rolled direction reached 221 MPa, 288 MPa and 14.1%, and those in the transverse direction reached 205 MPa, 280 MPa and 12.4%, respectively. The improved strength and decreased mechanical anisotropy resulted from the fine grain size and strong basal texture.