The homogenization on microstructure and mechanical properties of 2A50 aluminum alloy prepared by liquid forging was investigated.Wheel hubs were produced using direct and compound loading.The results show that the mi...The homogenization on microstructure and mechanical properties of 2A50 aluminum alloy prepared by liquid forging was investigated.Wheel hubs were produced using direct and compound loading.The results show that the microstructure and mechanical properties are inhomogeneous in direct forged samples.The microstructure of the wall is coarser than that of the base,and the mechanical properties are lower and some defects are detected at the wheel corner.Using compound loading,the microstructure and mechanical properties of the wall are improved evidently.With increasing feeding amount,the microstructure and mechanical properties become more homogeneous.The defects disappear when the feeding amount is 4 mm.The forged wheel hubs could obtain fine and homogeneous microstructure with grain size of 20-30 μm,tensile strength of 355 MPa and elongation of 10% when the feeding amount is 10 mm.The microstructure and mechanical properties of liquid forged workpieces could be controlled and homogenized using compound loading.展开更多
In this paper,45#steel supports prepared by liquid forging showed excellent performances and the effects of processing techniques on the development of microstructures and mechanical properties of these steel supports...In this paper,45#steel supports prepared by liquid forging showed excellent performances and the effects of processing techniques on the development of microstructures and mechanical properties of these steel supports were researched.The liquid forging process was simulated and technological parameters were optimized via a Pro CAST simulation software.The solidification time,temperature distribution,first principal stress distribution of the 45#steel supports varied with time,temperatures,and position.Two principal parameters,pouring temperature and dwell time,were assessed for their effects on microstructures,mechanical properties,and wear resistance properties of 45#steel supports.Results showed that the optimal pouring temperature of the molten metal and the pressure-holding time were between 1540℃ and 1560℃ and between 35 s and 40 s,respectively.The microstructure,mechanical properties,and fracture behavior of different positions in the support were also discussed,and the central position performed better than the edge because of plastic deformation.Finally,the dynamic solidification process was also investigated and the liquid forging process of 45#steel supports was complex and contained some special metal liquid convection and several plastic deformation stages.展开更多
The microstructures and mechanical properties of Al-8.3Zn-3.3Cu-2.2Mg alloys prepared via hot extrusion and liquid forging methods were investigated.Results show that based on DEFORM simulation analysis,the optimal ho...The microstructures and mechanical properties of Al-8.3Zn-3.3Cu-2.2Mg alloys prepared via hot extrusion and liquid forging methods were investigated.Results show that based on DEFORM simulation analysis,the optimal hot extrusion parameters are determined as ingot initial temperature of 380°C and extrusion speed of 3 mm/s.The hot-extruded aluminum alloy after T6 heat treatment presents superior mechanical properties with yield strength of 519.6 MPa,ultimate tensile strength of 582.1 MPa,and elongation of 11.0%.Compared with the properties of gravity-cast and liquid-forged alloys,the yield strength of hot-extruded alloy increases by 30.8%and 4.9%,and the ultimate tensile strength improves by 43.5%and 10.2%,respectively.The significant improvement in tensile strength of the hot-extruded alloys is attributed to the elimination of casting defects and the refinement of matrix grain and eutectic phases.In addition,the hot-extruded alloy demonstrates superior plasticity compared with the liquid-forged alloy.This is because severe plastic deformation occurs during hot extrusion,which effectively breaks and disperses the eutectic phases,facilitating the dissolution and precipitation of the second phases and inhibiting the microcrack initiation.展开更多
The microstructure and mechanical properties of nodular cast iron produced by the melted metal die forging process （MMDF for short） were experimentally researched.The main obtained results are ： the nodular cast ir...The microstructure and mechanical properties of nodular cast iron produced by the melted metal die forging process （MMDF for short） were experimentally researched.The main obtained results are ： the nodular cast iron produced by this process can be machined as easy as traditional one only if holding at the remained temperature for 4 h ; its strength and plasticity are obviously higher than those of traditional ones ; the graphite size arrived at grade 8 , and the graphite spheroidizing arrived at grade 1 or 2 , but a streamline molded distribution of the graphite slightly appeared.Both of the strength and plasticity increased with the pressure when the pressure holding time was larger than its critical value.A new way to produce high properties nodular cast iron was provided.展开更多
基金Projects (50774026, 50875059) supported by the National Natural Science Foundation of ChinaProject (20070420023) supported by the China Postdoctoral Science FoundationProject (2008AA03A239) supported by the National High-tech Research and Development Program of China
文摘The homogenization on microstructure and mechanical properties of 2A50 aluminum alloy prepared by liquid forging was investigated.Wheel hubs were produced using direct and compound loading.The results show that the microstructure and mechanical properties are inhomogeneous in direct forged samples.The microstructure of the wall is coarser than that of the base,and the mechanical properties are lower and some defects are detected at the wheel corner.Using compound loading,the microstructure and mechanical properties of the wall are improved evidently.With increasing feeding amount,the microstructure and mechanical properties become more homogeneous.The defects disappear when the feeding amount is 4 mm.The forged wheel hubs could obtain fine and homogeneous microstructure with grain size of 20-30 μm,tensile strength of 355 MPa and elongation of 10% when the feeding amount is 10 mm.The microstructure and mechanical properties of liquid forged workpieces could be controlled and homogenized using compound loading.
基金Project supported by the International Cooperation Project of the Ministry of Science and Technology of China(No.2014DFR50320)the National Natural Science Foundation of China(No.51174064)。
文摘In this paper,45#steel supports prepared by liquid forging showed excellent performances and the effects of processing techniques on the development of microstructures and mechanical properties of these steel supports were researched.The liquid forging process was simulated and technological parameters were optimized via a Pro CAST simulation software.The solidification time,temperature distribution,first principal stress distribution of the 45#steel supports varied with time,temperatures,and position.Two principal parameters,pouring temperature and dwell time,were assessed for their effects on microstructures,mechanical properties,and wear resistance properties of 45#steel supports.Results showed that the optimal pouring temperature of the molten metal and the pressure-holding time were between 1540℃ and 1560℃ and between 35 s and 40 s,respectively.The microstructure,mechanical properties,and fracture behavior of different positions in the support were also discussed,and the central position performed better than the edge because of plastic deformation.Finally,the dynamic solidification process was also investigated and the liquid forging process of 45#steel supports was complex and contained some special metal liquid convection and several plastic deformation stages.
基金Natural Science Foundation of Shandong Province of China(ZR2023QE193)。
文摘The microstructures and mechanical properties of Al-8.3Zn-3.3Cu-2.2Mg alloys prepared via hot extrusion and liquid forging methods were investigated.Results show that based on DEFORM simulation analysis,the optimal hot extrusion parameters are determined as ingot initial temperature of 380°C and extrusion speed of 3 mm/s.The hot-extruded aluminum alloy after T6 heat treatment presents superior mechanical properties with yield strength of 519.6 MPa,ultimate tensile strength of 582.1 MPa,and elongation of 11.0%.Compared with the properties of gravity-cast and liquid-forged alloys,the yield strength of hot-extruded alloy increases by 30.8%and 4.9%,and the ultimate tensile strength improves by 43.5%and 10.2%,respectively.The significant improvement in tensile strength of the hot-extruded alloys is attributed to the elimination of casting defects and the refinement of matrix grain and eutectic phases.In addition,the hot-extruded alloy demonstrates superior plasticity compared with the liquid-forged alloy.This is because severe plastic deformation occurs during hot extrusion,which effectively breaks and disperses the eutectic phases,facilitating the dissolution and precipitation of the second phases and inhibiting the microcrack initiation.
基金Item Sponsored by National Natural Science Foundation of China ( 51275031 )Innovation Fund for Technology Based Firms of China ( 11C26211304055 )
文摘The microstructure and mechanical properties of nodular cast iron produced by the melted metal die forging process （MMDF for short） were experimentally researched.The main obtained results are ： the nodular cast iron produced by this process can be machined as easy as traditional one only if holding at the remained temperature for 4 h ; its strength and plasticity are obviously higher than those of traditional ones ; the graphite size arrived at grade 8 , and the graphite spheroidizing arrived at grade 1 or 2 , but a streamline molded distribution of the graphite slightly appeared.Both of the strength and plasticity increased with the pressure when the pressure holding time was larger than its critical value.A new way to produce high properties nodular cast iron was provided.
