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An Al-7Si-1.5Cu-Mg alloy was synthesized through the modification of a commercial A356 alloy with the inclusion of alloying elements. This alloy underwent a treatment regime comprising solid solution, cryogenic treatment, and ageing. The results indicate that cryogenic treatment increased nucleation rate of precipitates, which increases the number of precipitates and reduces their sizes, ultimately improving the mechanical properties and reduce secondary dendrite arm spacing of the alloy. Under the optimal treatment conditions (solid solution at 520 °C for 10 hours, followed by deep cooling for 48 hours, and ageing at 160 °C for 10 hours), the secondary dendrite arm spacing of the alloy was reduced by approximately 37,5 %, exhibiting hardness of 102,8 HV and plasticity of 4,2 %.

The hollow slender shaft is characterized by intricate component features such as a significant depth-to-diameter ratio, variable cross-sections, and non-uniform thin walls. Uneven deformation of the hollow slender shaft during deformation results in degradation of service performance. In this study, the deformation uniformity is explored from a microscopic point of view, the numerical simulation model of dynamic recrystallization of 6061 aluminum alloy is established with the DEFORM-3D software. And grain evolution during the aluminum alloy extrusion process was theoretically analyzed using the cellular automata.

Aiming at the aerospace aircraft tie rod pipe fittings with indented riveted threaded bushing manufacturing, there are problems such as low connection strength, manufacturing cost and high weight, this paper innovates a new process of three-roll reduction and end extrusion thickening to form the aerospace thin-walled tie rods, and adopts the simufact finite element analysis (FEA) software to numerically analyse the forming process of the thin-walled fittings of A6061 aluminium alloy and analyse the equivalent plastic strain distribution, the change rule of the force-energy parameter, as well as the uniformity of the wall thickness in the process of rolling and squeezing, so that we can get the principle of rolling and squeezing forming and deformation rules of the thin-walled tie rods, and the results of the research provide the theoretical foundation for the domestic forming of the thin-walled tie rod pipe fittings.

In this paper, SiCp/TC11 titanium matrix composites were prepared by selective laser melting. The influence of laser process parameters on the forming quality of composites was studied by control variable method. The results show that the process parameters have a significant effect on the forming quality of the composite material. The laser power has the greatest influence on the density, followed by the scanning spacing, and the scanning speed has a relatively small influence. When the laser power is 160 ~ 180 W, the scanning speed is 1 000 ~ 1 200 mm/s, and the scanning spacing is 0,1 mm, the forming quality of the sample is better.

Aiming at the large weight of automobile steel solid shaft, this paper innovates aluminum alloy hollow shaft. The rolling process of automobile hollow shaft was simulated by using the short process flexible precision forming process and the Finite Element Method (FEM). The variation of the shape and inner hole of the rolled piece, the roundness of the outer surface and the wall thickness during the rolling process were analyzed. The numerical results verify the feasibility of rolling aluminum alloy automobile hollow shaft by this process, and provide a theoretical basis for forming aluminum alloy automobile hollow shaft in China.

This study focused on the microstructure evolution of non-oriented Fe-3,0 %Si steel used in the core of new energy vehicle drive motor. An hot band and a sample normalized at 800 °C for 10 min were subjected to a moderate cold rolling and an annealing treatment. The results show that the initial hot band has gradient microstructure. After normalizing, the surface is consisted of fine recrystallized grains, the central layer has elongated α-fiber and γ-fiber grains, the subsurface shows a mixed grain structure with strong Goss texture. After cold rolling with a thickness reduction of 40 %, α-fiber and γ-fiber textures are strengthened, and unstable Goss texture disappears. After annealing at 700 °C for 5 min, gradient recrystallization occurs and γ-fiber texture is weakened. The central and subsurface layers show frequently nucleation phenomena in the grain interior and grain boundaries, resulting in strong Ѳ-fiber, α*-fiber and Goss components.

In order to improve the comprehensive performance of titanium alloy, the mechanical ball milling method was used to optimize the preparation of composite powder by different ball milling time, rotation speed and SiCp content. SiCp/TC11 composites were prepared by selective laser melting (SLM) technology. The results show that the milling speed, time and SiC content have an effect on the morphology, size and distribution of the composite powder. Compared with TC11, the hardness of the composite prepared by SLM process is 426,723 HV, which is increased by 15,10 %, and the enhancement effect of SiCp is successfully realized.The research results provide a theoretical basis for obtaining high-quality aerospace titanium alloy parts.

The structural characteristics of the car shift tower cover were analyzed, and the pouring system and overflow system were designed according to the empirical formula.The numerical simulation based on Anycasting software shows that the metal liquid flow and solidification rate of the initial process are not smooth.According to the simulation results, the shape of the runner and the number of the gate were modified, and the point cold water pipe was set at the position where the defects might occur to optimize the process.The numerical simulation of the optimized process scheme shows that the filling process is stable and there is no liquid spatter, and good quality die casting is obtained through actual production.

Aiming at the problem that the wall thickness uniformity of conical thin-walled aluminum alloy parts formed by single-pass spinning is difficult to control, this paper systematically studies the influence of different spinning parameters on the material evolution law and load mechanism during the forming process of 1070 thin-walled aluminum alloy. The effects of slab thickness, roller gap and feed ratio on the macroscopic forming quality and mechanical load of 1070 thin-walled aluminum alloy conical parts were simulated by Simufact.forming software. Finally, the optimal spinning parameters of 1070 thin-walled aluminum alloy conical parts were obtained. The final results show that increasing the diameter-thickness ratio of the blank can prevent wrinkling, and reasonable spinning parameters can improve the uniformity of the wall thickness of the product.

High temperature nickel-based alloys are prone to forming defects due to serious work hardening, and the pass spacing is an important parameter in multi-pass drawing and spinning. Using GH4169 superalloy as the material, a Finite Element Model (FEM) was established based on the Simufact platform, and the influence of the pass spacing on the spinning process was explored by using the concave curve and circular arc trajectory. The results show that the stress-strain increases with the increase of the pass spacing. Obtain the optimal pass spacing under specific conditions: blank wall thickness t = 2,5 mm, blank diameter d = 250 mm, feed ratio f = 1,2 mm/rad, mandrel speed n = 300 r/min, pass spacing p = 14 mm.

In this paper, Simufact FE software is used to establish a simulation model of three-roll diagonal roll piercing integrated forming flange nut blanks, elaborate its process principle, analyze its forming process through numerical simulation. The law of load change, equivalent plastic strain distribution and wall thickness uniformity during the piercing process and diameter reduction process were investigated, and verify the feasibility of this forming process for manufacturing flange nut blanks.

In this paper, the forming mechanism of 3103 aluminum alloy forming deep cylinder part under ten passes spinning is studied. The forming process of each step is simulated by finite element method. The distribution characteristics of equivalent stress field and strain field in forming were analyzed in detail. The influence of feed ratio on spinning force is obtained. By measuring the thickness and circularity of the final forming deep cylinder part, the final forming effect of multi-pass spinning is obtained.

The paper introduces a new technology of the integrated forming of shape and inner hole of hollow axle. Firstly, the design of the process is described. Secondly, the range of feed angle of two sets of rolls and the principle to be followed are explained. Finally, the rolling process of hollow axle is simulated by Finite Element Method (FEM), and the variation law of load parameters and the distribution law of temperature and effective plastic strain in the rolling process are analyzed.The numerical results verify the feasibility of rolling hollow axle with this process.

With the deepening and popularization of the cross wedge rolling process, the requirements for the cross wedge rolling blanks have become wider and wider. Relying only on the traditional round blanks will restrict the promotion of the cross wedge rolling process to a certain extent. The emergence of the square billet is a breakthrough in the selection of raw materials, but related research is relatively scarce. Therefore, this paper conducts a finite element simulation for the rolling process of the square billet. Four characteristic points are taken on the longitudinal section of the billet to track the temperature change. Research on the law of field changes. At the same time, the change of the grain size and dynamic recrystallization percentage of the rolled piece during the rolling process is studied. Simulation and experiment are combined to obtain the change rule of the average grain size of the characteristic points of the longitudinal section of the billet with time.

This paper mainly studies the influence of process parameters on the forming quality during the spinning process of 6061 aluminum alloy wheel forging blanks. The four parameters of spinning temperature, spindle speed, wheel feed and wall thickness reduction rate are selected for research, and the quality of the surface of the hub and the influence on the size of the hub are judged. Simufact software is used to simulate the influence of various process parameters on the forming quality of the hub. The results provide a certain reference for the reasonable selection of process parameters during the spinning forming process of 6061 aluminum alloy hub.

In order to improve the forming quality of cross wedge rolling of gear shaft teeth, this paper adopts the single factor research method and uses DEFORM - 3D software to carry out the finite element simulation of the rolling process with different feed rate dies.The results show that the total feed rate of 2,75 mm is the most appropriate, and the tooth top defect of rolled piece gear can be repaired under this condition. The feed rate in the first stage is more important than that in the other stages, and the suitable range of it is 1,0 mm - 1,2 mm.

Aircraft joystick pipe is the key part of aircraft hard control system. In this paper, a hollow necking rod pipe made of aluminum alloy 2A12 is taken as the research object. The tapered roller with extrusion cone on one side of the roller surface is designed. Simufact.Forming14.0 was used to analyze. It was found that the radial rolling force at the end of the thickening section in the second pass increased sharply. At this time, the retaining part inhibited the axial extension of the metal and realized the accumulation in the thickness direction. The thickening rate and effect were favorable at 120 rpm, which provide a theoretical basis to realize integrated forming of aeronautical thin-walled aluminum alloy tube.

This paper mainly studies the effect of process parameters on the deformation mechanism of MZ21 magnesium alloy and 7075 aluminum alloy bimetal composite pipe in spinning process.The two parameters of spinning, the rotary wheel feed ratio and the double tube wall thinning rate were selected to study, and the influence rule of each process parameter on the forming quality of composite tube was simulated by Simufact software. Under different thinning rates of the total wall thickness, the coordinated deformation and the rebound law of the wall thickness of the composite pipe are obtained. The results provide a certain reference for the preparation of magnesium aluminum composite pipe and the selection of reasonable spinning parameters.

In order to better control the forming quality of copper ball by warm skew rolling process, a Finite Element Model (FEM) of copper ball warm skew rolling for the coupling of thermal and mechanical was established. The influence of process parameters on force and rolling torque was analyzed by using single factor research method. The results show that the smaller the cross angle, the lower the rolling temperature, the slower the rolling rotation speed, the greater the forming force and rolling torque, the more difficult for forming. The optimum rolling temperature is 600 °C; the optimum cross angle is 2,5°; the optimum rolling rotation speed is 60 rpm.

This paper takes the simplified high-speed train hollow axle variable diameter section sample as the research object, uses Simufact.Forming simulation software for simulation, analyze the rolling piece inner variable diameter section, equal diameter section, outer variable diameter section three stages in the forming process of temperature field distribution characteristics and variation, and discusses the causes of temperature field variation.

In the process of TRSR hollow axle, there is metal reflow on the surface of the rolled piece, which greatly reduces the forming accuracy of the rolled piece. To solve this problem, it is necessary to study the metal reflow law of axle body. First, the flow law of metal on the surface of rolled piece is obtained by point tracking method. Moreover, the effects of process parameters on the metal reflow degree of axle body are carried out, and the influence law of process parameters on the metal reflow degree of axle body is obtained. Finally, by comparing the results of the experiment and the simulation, the reliability of the simulation is proved.

The microstructural evolution of MgY12Zn2,5 magnesium alloys was observed, and the strengthening and toughening mechanism of the alloys were studied. The results showed that the MgY12Zn2,5 alloy after solution treatment with higher content of 14H - LPSO (long - period stacking - ordered structures) could more effectively inhibit the recrystallization and growth of recrystallized grains, and the microstructure was more fine and uniform. And its tensile strength (Rm), yield strength (Rv) were 395 MPa, 308 MPa and elongation (A) 17,5 %, respectively. In contrast, the MgY12Zn2,5 alloy treated at 470 °C for 24 h, whose Rm, Rv, were only 376 MPa, 282 MPa and A 15,5 %, respectively.

This paper adopts a three-roll skew rolling technology with rolls that can either converge or move apart to form shafts with variable cross-section dimensions. Based on the rolling pitch, the effect of rollers’ rotation speed, radial speed, axial speed of chuck on the forming accuracy of the hollow shaft surface is analyzed. Increasing the rotation speed of rollers, reducing the radial speed of rollers and the axial speed of chuck can obtain higher surface forming accuracy. The finite element simulation results verified the correctness of the conclusion.

The spiral marks is one of the main surface quality defects of the three-roll skew rolled hollow axles. In order to eliminate the spiral marks, it is necessary to clarify the cause of the spiral marks on the surface of the rolled piece. Based on the analysis of the kinematics of the three-roll skew rolled hollow axles, the spiral marks is caused by the spiral pitch of the rolled piece being larger than the width of the finishing section of the roller. Increasing the rotation speed of the roller can reduce the spiral pitch of the rolled piece, thereby avoiding the appearance of spiral marks. The correctness of the proposed condition for preventing the defect of spiral marks is verified by simulation.

The laminated shafts were prepared by CWR process. The heat treatment study was carried out to enhance its properties. The shafts were treated by different annealing processes, the changes of properties before and after annealing were compared. The microstructure and the tensile fracture were analyzed. The results showed that the tensile and shear properties of the laminated shafts were the best when annealing at 700 °C for 60 min, which could reach 576 MPa and 473 MPa, respectively. After annealing, fine interfacial spheroidal structure could be obtained and enhanced the bonding strength; the dimple holes at the tensile fracture became larger and deeper, and the fracture became uniform and stable, clarified the reasons of the change of mechanical properties.

The average grain size and microstructure uniformity are the key factors determining the mechanical properties of the hollow shaft. In order to obtain a fine and uniform microstructure, a finite element model of threeroll skew rolling hollow shaft for the coupling of heat, force and microstructure was established. The influence of process parameters on the average grain size and microstructure uniformity of the rolled product was analyzed by using the single factor research method. The results show that the grain size is remarkably refined and the distribution is relatively uniform. The optimum rolling temperature is 1 050 °C; the optimum feed angle is 9 °; the optimum roll rotate speed is 90 rad/min.

In order to reasonably select the process parameters of the rolling process of 30CrMoA steel, the rheological characteristics of 30CrMoA steel at high temperature were studied. First, the stress-strain curve of 30CrMoA steel in the temperature range of 1 223 K to 1 423 K and the strain rate of 0,01 s-1 to 10 s-1 was obtained through thermal simulation experiments. Then an empirical constitutive model was established, and the material constants in the established constitutive model were determined by regression analysis of experimental data. Finally, the accuracy of the constitutive model of 30CrMoA steel was verified. The results show that the error between the calculated value and the experimental value is within 5 %, which indicates that the 30CrMoA steel constitutive model has high accuracy.

Reasonably determination of the rolling temperature of the cross wedge rolling (CWR) is the key to o btain the qualified surface of the aluminum alloy shaft parts. In this paper, the 6 082 aluminum alloy shaft parts with different section shrinkage rate between 43,75 % and 64 % are taken as examples. The thermal-deformation coupling finite element model (FEM) is established to analyze the effect of the process parameters on the temperature field. The influence law of the temperature field on the surface quality in CWR process is obtained and verified by experiment. The results provide theoretical and experimental basis for temperature selection and surface quality improvement.

Using conical end blanks is an effective method to improve the concave defects of cross wedge rolling, while the common method to get conical end blanks is machining, still causing material loss. Aimed at this situation, this paper proposes a roll-cutting forming method of conical end blanks based on metal-plastic forming. In order to clarify the rollcutting forming mechanism of the conical end, the displacement field and strain field variation during the forming process of the conical end are analyzed based on finite element simulation analysis, and the metal flow during the roll-cutting process is obtained. Moreover, the conical end blank formed by roll-cutting is sent to cross wedge rolling, the results verify the feasibility of roll-cutting conical end blank used for cross wedge rolling without stub bar.

In order to expand the range of the cross wedge rolling (CWR) product, realize CWR of hexahedral blank. In this paper, the three-dimensional Finite element model (FEM) of hexahedral blank CWR is established by DEFORM finite element software. The influence of forming angle, spreading angle and section shrinkage on the length of concavity is analyzed, compared with the round billet rolling results under the same parameters, the concavity length of the hexahedral blank is slightly larger than that of round billet, and the influence of process parameters on the concavity is basically the same. The research results provide theoretical guidance for the rational determination of process parameters for CWR of hexahedral blank.

In order to study the influence of process parameters on the forming force during the forging and spinning process of the wheel hub, five parameters were selected: die preheating temperature, blank temperature, upper die down speed, friction coefficient and feed rate.Use Deform and Simufact software to simulate and obtain the influence law of each process parameter on forming force. The results provide a certain reference for reasonable selection of process parameters in the forming process.

Shaft grain size and uniformity play an important role in improving its mechanical properties. Using DEFORM-3D finite element software, the effects of broadening angle and forming angle on the micro performance of the GH4169 alloy shaft parts were studied systematically. The results show that grain refinement is mainly completed in the stretching section. As the broadening angle increases, the grain size expands constantly, and the fluctuation value decreases and then increases, while as the forming angle increases, the grain size and the fluctuation value decrease and then increase. The accuracy of the finite element model was verified through cross wedge rolling experiments.

A three-di mensional rigid-plastic Finite element model(FEM) for cross wedge rolling of square billet was established by using DEFORM finite element software. The influence of forming angle, broadening angle and section shrinkage on the volume of one-sided blank head was analyzed based on orthogonal experiments of three factors and three levels. It is concluded that the influence degree of forming angle, section shrinkage and broadening angle on the volume of one-sided blank head decreases in turn, and the influence degree of corresponding process parameters in different sections is also different. The results of this study can provide references for expanding the types of cross wedge rolling billets and choosing reasonable process parameters in square billet rolling.

In order to solve the problem of large springback in higher D/t cylinder stamping, the method of hydroforming following drawing is adopted in this paper. It can reduce the residual stress of the cylinder after heat treatment. The effects of the stretching height, hydraulic pressure and blank holder force on the cylinder quality are investigated using the finite element software dynaform, and the optimal process parameters are obtained. In case that the stretching height, blank holder force and hydraulic pressure are relatively 55 mm, 12,5 MPa and 20 KN, the rate of wall thickness variation and springback are obviously reduced. The research results lay a theoretical foundation for improving the plastic deformation of thin-walled cylinder.

This paper presents the new technology applied in a three-roll skew rolling railway hollow shaft. The three-roll skew rolling forming simulation is conducted in railway hollow shaft with 1 : 5. The rotation condition of the three-roll skew rolling is deduced and the rolling force and rolling torque are calculated and validated. The influence of process parameters on mechanics parameter is analyzed, from which it concludes that the mechanics parameters of the skew rolling are obviously smaller than those acquired by the cross-wedge rolling when rolling the same size of the railway hollow shaft. The results of this study lay a theoretical foundation for the realization of accurately forming the three-roll skew rolling railway hollow shaft with short process and low cost.

To eliminate internal void and improve the mechanical properties of steel balls formed by skew rolling, the floatingpressure method (FPM) using high-pressure gas to compact void is applied in this paper. By establishing void closure mechanical model, effects of various factors on void closure are obtained. The change rule of microstructures and outline of steel ball is investigated using DEFORM-3D Finite element software, and results show that when void is entirely closed, steel ball diameter decreases by less than 2 %, and its dimensional accuracy is guaranteed; the dynamic recrystallization of the metal around void promotes the healing of micro-cracks. The FPM experiments are performed, which verify the accuracy of the finite element model.

To improve mechanical properties of asymmetrical hollow shafts parts, the dynamic recrystallization of asymmetrical hollow shaft can be obtained by cross wedge rolling (CWR) technology. The Finite element model (FEM) is established using the DEFORM-3D software, the distribution of the dynamic recrystallization volume fraction is illustrated, and the law of average grain size distribution is analyzed. The microscopy results indicate that the grain size at the central area of cross-section is larger than that at lateral area, and the grain of the central part can be obviously refined, the whole microstructure homogeneity is improved, which have provided theoretical foundation for further improving the quality and mechanical properties of CWR asymmetrical hollow shafts parts.

The paper presents a new method of one closed cross wedge rolling (CWR) based wedge block to achieve near net forming of CWR shafts. The modeling is performed by using the Finite Element Method (FEM) software DEFORM-3D. The metal flow rule of the shaft is clarified by analyzing the strain and displacement field of the shaft. The results demonstrate that the concave heart value of rolled part end will be reduced by about 70 % by one closed CWR based wedge block, comparing it with the case without wedge block. And also the rolling experiments are performed the result of which provides reliable theoretical basis for achieving near net forming of CWR.