Speed Stamping Research Articles

Influence and improvement of stamping process parameters on V-shaped clamp forming quality

Aiming at the problems that a V-shaped clamp is easy to crack, wrinkle, and springback in the stamping process, a method to improve forming quality by setting the best stamping process parameters is put forward in this paper. The stamping process of the V-shaped clamp was simulated by using the software of ABAQUS, which showed that the stamping process parameters, such as friction coefficient, stamping speed, and mold gap, can affect the forming quality. The optimal combination of stamping process parameters was obtained through an orthogonal experiment. Simulation, profile dimensional measurement, and Fuji paper test were conducted to evaluate and examine the quality of V-shaped clamps before and after optimization. According to the findings of the study, the stamping speed is the main factor affecting the simulation results. The comprehensive effect of the maximum thinning rate, maximum thickening rate, and maximum springback is the best with the stamping speed of 10.00 mm·s−1. The ideal specifications for the stamping process are a 0.16 friction coefficient, a 10.00mm·s−1 stamping speed, and a 2.20 mm mold gap. Process parameter modification can greatly increase the dimensional accuracy and mechanical properties of molded parts.

Effect of process parameters on AA6061/Q345 bimetal composite for hot stamping

Hot stamping is an advanced forming process used in automobile lightweight manufacturing, but it has not been used in the manufacture of bimetal composite parts. In this work, based on the hot stamping forming technology and the advantages of bimetal composite in strength, stiffness and corrosion resistance, the finite element simulation theoretical analysis and test on the hot stamping forming of AA6061/Q345 bimetal composite U-shaped parts were performed. The effect of initial temperature, stamping speed, die gap and pressure holding time on forming quality were investigated. The results show that the initial temperature not only affects the temperature distribution of each layer of the bimetal composite after stamping but also affects the deformation resistance during forming. The increasing stamping speed reduces the contact time between the die and plate rising the plate temperature, but the increasing stamping speed also strengthens the stamping hardening effect in the forming process leading to the stress increase. The die gap affects the contact area between the plate and the die. The increasing gap is beneficial to reduce the temperature difference between different layers. However, an excessive die gap also increases the tensile stress in the plate and affects the forming accuracy. With the pressure holding time larger, the temperature of the formed part becomes low, the residual stress releasing causes the stress to be smaller. According to the analysis of tensile and bending mechanical properties, it is indicated that the formed parts prepared by the optimal parameters obtained by numerical simulations have excellent mechanical properties and formability.

Parameter Optimization of Hot Stamping for an Extension Part Based on DYNAFORM under the Background of New Engineering

Based on the finite element analysis software eta/DYNAFORM, the hotstamping mo del of the front longitudinal beam on an extension part was established. The finite element numerical simulation of the beam was carried out by the method of thermal coupling. The effects of different stamping speed, holding time, and temperature field and friction factor on forming quality were analyzed. The results show when the stamping speed of 200 mm/s, the holding time of 6s and the friction factor of 0.4, the martensite content is relatively higher and the springback is smaller. It provides an important basis for reasonable technological parameters of ultra-high strength parts, and also provides technical support for the new engineering construction.

Research on the Compound Process of Hot Stamping and Heat Treatment for Duralumin Alloy Fairing with Large Aspect Ratio: Experiment and modeling

The compound process of hot stamping and solution quenching heat treatment (HFQ®) was utilized to fabricate hard aluminium fairing of high aspect ratio. A simulation model was established by MSC.Marc to optimize the shape and size of the blamk as well as the effects of process parameters, namely, initial temperature, stamping speed, blank holder force (BHF), on extreme final temperature and thickness distribution of formed component were investigated. The reliability of finite element simulation was proved by the hot stamping experiments with self-designed moulds under the optimize process parameters achieved by simulation results. The results indicated that the optimized blank is well deformed without flange wrinkle and broken round; the maximum cooling rate in quenching can inhibite the precipitation when the initial temperature ranges from 350 to 450℃; BHF effects dominated on thickness distribution and 10KN is the most reasonable value under the studied condition while the optimum stamping speed is 100mm•s-1. Compared with the thickness of the stamping trials and numerical simulation, the deviation is less than 3.6%. Furthermore, The desired mechanical property is achieved without significant inhomogeneity.

Research on Progressive Die Design for Asymmetric U-Shaped Contactor

The pressing technologies and the forming difficulties of the asymmetric U-shaped contactor were analyzed. The strip layout was designed for progressive pressing from piercing to bending. The die structure was designed in three plates mode, guiding with ball cage bush and pillar mechanism. The multiple steps bending stations and sliding inclined wedge mechanism were designed to implement the critical forming function. The volume production proved that this toolset’s structure was robust at high stamping speed and the products meet the high quality criteria. A valuable universal design rule was concluded for similar product’s toolset design.

Investigations on the variation of corrosion and contact resistance characteristics of metallic bipolar plates manufactured under long-run conditions

Tribological variations, surface conditions (roughness, hardness, coating) and surface interactions between micro-stamping dies and bipolar plate blanks play a critical role in determining the surface quality, channel formation and precision of bipolar plates. This study is aimed to understand the cause, mechanism and consequences of interactions between micro-stamping process conditions and bipolar plate quality. A total of 2000 repeated micro-stamping of 51 μm-thick uncoated and 1 μm-thick ZrN coated SS316L sheet blanks into an array of 750 μm micro-channels were performed using 175–220 kN force levels with constant stamping speed of 1 mm/s. Microscopic examinations were conducted periodically on both die and coated & uncoated plate surfaces to observe topographic variations. In addition, corrosion and contact resistance tests were carried out in the same intervals. Analysis of variance (ANOVA) technique was used to determine the significance of the process parameters on channel height, roughness, corrosion and contact resistance differences. The results revealed similar roughness trends for die and plate surfaces during 2000 micro-stampings. ZrN coating with 1 μm thickness dramatically improved corrosion and contact resistance behavior of plates.

Forming Response of Ultra High Strength Steel Sheet to Stamping Speed during Hot Forming

Stamping speed is an important parameter in sheet metal forming especially in hot forming. In this study, hot forming of a U-shaped part made of ultra high strength boron steel (22MnB5) sheet is simulated with solid elements. The mechanical properties of 22MnB5 steel sheet and the key process parameters are introduced in detail. Emphasis is laid on the forming response of the boron steel sheet to stamping speeds of 3.25m/s, 0.325m/s and 0.0325m/s. The mechanism of stamping speed acting on hot formability and temperature field of the stamped part is analyzed. It is demonstrated that stamping speed affects both formability and the heat transferred from blank to tools and to environment during hot forming. And the coupling effect of material properties, the heat produced during plastic deformation and heat boundary condition decides the formability and temperature field. An appropriate stamping speed is more important for hot forming than that for common cold forming.