Two-stage magnetic-elasto-pulse stamping of thin sheet parts

The article substantiates the use of preliminary static loading and subsequent forging force when stamping thin sheet parts of complex shape with an elastic punch. The static load provides a relative deformation of the order of 20– 30% in the processing zone, which guarantees the stability of the position of the workpiece during subsequent pulsed loading. This technique is very important in the manufacture of asymmetric parts with a thickness of 0.01 – 0.3 mm. As a result, the accuracy of the products obtained corresponds to the 7th grade.The article provides a schematic diagram and a description of the proposed design of a double-action press, and analyzes the cyclogram of the device.It is recommended to carry out a static load with an electric drive, a pulsed one with a magnetic hammer, which is connected to a generator of impulse currents with a capacitive storage with an energy capacity of up to 40 kJ with a natural discharge frequency of the current of 20 kHz.

FEM Simulation of Multi-Stage Forging for Dray Fasteners

This study uses the dies of the dray fasteners processing graphics provided by the fastener’s industry to establish 3D dies and components solid models based on the embedded drawing function tools provided by the component model (Standard.ipt) of Autodesk Inventor CAD software. After finishing the dies and components drawing, the integrated assembly drawing of dies can be obtained through the assembly model (Standard.iam) firstly. Three stages forming processes can be conducted and carried out the FEM simulation to check the forming acceptance. The effective stress, the effective strain, the velocity field, and the forging force can be obtained by the FEM simulation. Moreover, the realistic experiment can be performed to verify the acceptance of FEM simulation. The dimensions of final product can be measured to get the errors between FEM and experiment. It is noted that the errors show a good agreement with the experiment.

Flow Stress and Friction of AL6061 and Application to the Cellphone Shell Forging

Predictive power and final shape are very important in the forging process. This study used a finite element method to analyze the forging force, final shape and stress distribution of the cellphone shell forging at different temperatures. To predict the results of FEM simulation accurately, the stress flow and friction factor play an important role. The AL-6061 stress-strain curve at different temperatures was obtained from the compression test of the universal material testing machine. The friction factor between Al-6061 alloy and die is determined by ring compression test.The stress-strain curve and friction factor are applied to the finite element analysis of cellphone forging. Finite element analysis is used to determine the maximum forging load, effective stress distribution and shape of cellphone shell forging. Then the cellphone shell is forged with the parameters of finite element analysis results. Finally, the forging force and product shape are compared between the experimental data and the simulation results. The dimension of the cellphone shell agree with the initial design and the forming force does not exceed the maximum allowable forging load of the machine.

Application of FEM and Abductive Network to Determine Forging Force and Billet Dimensions of Near Net-Shape Helical Bevel Gear Forging

In this paper, the use of the finite element method in conjunction with abductive network is presented to predict the maximum forging force and the volume of billet during near net-shape helical bevel gear forging. The maximum forging load and volume of billet are influenced by the process parameters such as modules, number of teeth, and die temperature. A finite element method is used to investigate the forging of helical bevel gear. In order to verify the prediction of FEM simulation for forging load, the experimental data are compared with the results of current simulation. A finite element analysis is also utilized to investigate the process parameters on forging load and volume of billet. Additionally, the abductive network was applied to synthesize the data sets obtained from the numerical simulation. The prediction models are then established for the maximum forging load and volume of billet of near net-shape helical bevel gear forging under a suitable range of process parameters. After the predictions of the maximum forging force and the volume of billet, the optimum of the power of forging machine and the dimensions of billet are determined.

Generalized optimizations of two-stage forging of micro/meso copper fastener

Three are generalized simulation optimizations considering the forging force, the die stress, and the dual-goals in two-stage forging of micro/meso copper fastener. Constant shear friction between the dies and workpiece is assumed to perform multi-stage cold forging forming simulation analysis, and the Taguchi method with the finite element simulation has been used for mold-and-dies parameters design simulation optimizations considering the forging force, die stress, and dual-goals. The die stress optimization is used to explore the effects on effective stress, effective strain, velocity field, die stress, forging force, and shape of product. The influence rank to forging process of micro/meso copper fastener for three optimizations can be determined, and the optimal parameters assembly consider die stress can be obtained in this study. It is noted that the punch design innovation can reduce the forging force and die stress.

Microstructure and mechanical characteristics of hot forged lateritic steels

The current development of steel industry has constraints on the availability of raw materials, so we have developed local raw materials that are lateritic steels as a high potential for alternative manufacturing of steel. This research was conducted to understand the characteristics of lateritic steel through hot forging process by the mechanical and microstructure behaviour. The research methodology was chained by variety of preheating temperature of 800; 1000; 1200 °C and forging force from 0 until 1000 kilonewton. In case of hot forging values was obtained the impact and hardness properties also microstructure that compared with as-cast steels. The results of impact strength increased by 81.83% at the temperature of 1200 °C and the hardness increased by 4.99% at 1000 °C, for the microstructure analysis was produced the ferrite and pearlite phases with the fine grains. The chemical composition of steel is classified in low carbon steel included in lateritic steel it contains low alloy 1.78 Ni and 0.553 Cr %wt.