Advanced Materials Research Vols. 602-604

Abstract: On the basis of analyzing the process of supporting bar forging conform, the 3D solid geometries modeling of billet and die were constructed by SOLIDWORKS software, the distributions of die stress and contact stress on the process of supporting bar forging conform were analyzed by using DEFORM-3D program. The working life of the die punch was assessed. The die structure was optimized based on the simulation results, and the forging defect of the improved work piece could be well controlled and the die working life was improved to about 10%.

Abstract: A phase-field model based on the Ginzburg-Landan theory and KKS model is used to simulate the dendrite growth of multiple grains for Al-Cu alloy. The influence of solidification latent heat and undercooling on the growth of equiaxed dendrite, solute distribution and temperature distribution were studied. The results show that the dendrite has well-developed and the competitive growth between grains more intense with the increasing of undercooling. The release of solidification latent heat restrain dendrite growth to a certain extent, which led to the less developed growth of dendrite solidified in non-isothermal conditions than that in isothermal conditions.

Abstract: For researching the stress and strain field distribution and the effect of process parameters on forming quality in the precision forming process of mid-thick nut plate, this paper builds the nut plate 3d parts of precise forming finite element entity model in ABAQUS software, and then uses Johnson-cook model to describe the material constitutive relationship and metal material damage and fracture. The ALE adaptive technology has been used to control material large deformation in finite-element analysis of elastic-plastic. Based on this model, this paper analyzes the stress and strain field distribution,average pressure stress distribution and metal material plastic flow rates distribution, and the influence of the process parameters on the forming quality in the forming process.

Abstract: With the rapid development of road transport enterprise and the popularity of car trailer transport, semi-trailer has become the main means of transport of road freight. So the semi-trailer manufacturing has become an important component part of the auto industry. Speed and heavy duty are the long-term pursuit of the High-speed transport, the key to solving this problem is a component of lightweight, while the hollow axle is the important one. The hollow axle manufacturing process, with many process factors, is more complex than the solid one. Therefor, the research on the hollow axle manufacturing process is very necessary.

Abstract: Electromagnetic riveting is a kind of energy conversion technology and forming coil is the key component of energy conversion. Coil parameters include the turns and wire cross section size. The effects of coil parameters on discharge current, riveting force, rivet deformation degree and energy conversion rate were investigated by experimental method in low voltage electromagnetic riveting. The results show that with the coil turns increasing, coil inductance increases, discharge current amplitude decreases, cycle increases, rivet deformation degree increases and the energy conversion rate improves when the coil wire cross section size is the same. And with the coil wire width increasing, the coil resistance decreases, discharge current amplitude increases, rivet deformation degree increases and the energy conversion rate improves when the coil turns is same. By rational design of coil turns and wire section size, low voltage electromagnetic riveting is an effective way to realize deformation of strain rate sensitive material TA1 rivets.

Abstract: Based on the rigid-plastic FEM program DEFORM-3D, the forming process of roll-forging for the thick-walled hollow parts has been simulated. The effect reduction on elongation and width-extension has been presented, and the difference between hollow part and solid part has been investigated in elongation and width-extension. This project can provide a reference for guiding the actual roll-forging for thick-walled hollow part.

Abstract: With physical experiments and numerical simulation about semi-ball bottom cylindrical parts and flat-bottomed cylindrical parts, we got the thinning law about spherical bottom of semi-ball bottom cylindrical parts, and got forming limit height difference of semi-ball bottom cylindrical parts and flat-bottomed cylindrical parts under the same conditions. In accordance with the principle of constant volume, the cylindrical ball height of semi-ball bottom cylindrical parts can be converted to draw from the cylindrical part height of the flat-bottomed cylindrical parts, which introduced a method of calculating the forming limit height of semi-ball bottom cylindrical parts. Through practical examples, this algorithm is feasible.

Abstract: The effects of stamping process parameters (blank thickness, blank holder force, friction coefficient, die clearance) on the formability of an automobile reinforced plate were investigated. The process parameters are optimized based on the results of orthogonal testing. The optimal process parameters were obtained by simulation result analysis of variance. The accuracy of numerical simulation is verified by the experiment, which provides guidance for the actual production.

Abstract: The unreasonable residual stress field in sheet part has an adverse effect on the dimensional accuracy and performance. A forming method combined stamping and forging was proposed to reduce the residual stress of the sheet part. The residual stress field in 2024 aluminum alloy V-shaped piece after bending and forging was analyzed by the finite element software Abaqus. The results showed that the stamping-forging forming process can significantly reduce the residual stress in round corner of V-shaped piece, and simultaneously decrease springback and improve the dimensional precision of sheet part.

Abstract: The warm forging process of spur gear with large module using floating die set was studied in the paper. The influence of process parameters such as billet temperature, web position, web thickness, frictional factor on the filling of die cavity and forging load were investigated by finite element method. It was concluded that the corner filling of gear can be improved by using free floating die. The forging load decreased with the increase of billet temperature or the decrease of frictional factor. The best web position for die cavity filling was that the web was located in the middle of the forged part.