Showing papers on "Stamping published in 2013"

Hot stamping of AA5083 aluminium alloy sheets

Abstract: The paper is aimed at proving the feasibility of producing sheet components by stamping AA5083 sheets at elevated temperature and strain rate. Laboratory tensile and Nakajima-type tests were carried out to evaluate the material flow stress, ductility and fracture limits sensitivity to temperature and strain rate, and therefore to determine the optimal combination of process parameters assuring both maximum formability and effective post-deformation mechanical properties. Industrial trials were conducted on an automotive component to validate the laboratory results.

About the influence of stamping on thermoplastic-based composites for aeronautical applications

Abstract: An experimental study has been conducted to investigate changes in the mechanical behavior of carbon woven ply PPS laminates, obtained from thermo-compression, for aeronautics purposes. The influence of stamping on mechanical properties (tensile, compressive, in-plane shear, inter-laminar shear) of PPS-based laminates under severe environmental conditions (120 °C/hygrothermally aged) has been quantified, as well as for structural testing conditions (bolted joint). From the meso-structure observations, two important phenomena, re-compaction of fiber network and migration of resin melt, can be associated with the re-consolidation process of C/PPS laminates during stamping. This second thermo-compression improves the impregnation of fiber bundles by the PPS matrix and the interlaminar adhesion, which can be correlated with higher mechanical properties of PPS-based laminates under severe conditions.

Grcop-84: A High-Temperature Copper Alloy for High-Heat-Flux Applications

Abstract: GRCop-84 (Cu-8 at% Cr-4 at% Nb) is a new high-temperature copper-based alloy It possesses excellent high-temperature strength, creep resistance and low-cycle fatigue up to 700 C (1292 F) along with low thermal expansion and good conductivity GRCop-84 can be processed and joined by a variety of methods such as extrusion, rolling, bending, stamping, brazing, friction stir welding, and electron beam welding Considerable mechanical property data has been generated for as-produced material and following simulated braze cycles The data shows that the alloy is extremely stable during thermal exposures This paper reviews the major GRCop-84 mechanical and thermophysical properties and compares them to literature values for a variety of other high-temperature copper-based alloys

Enhanced Mechanical Properties of a Hot-Stamped Advanced High-Strength Steel via Tempering Treatment

Abstract: The hot stamping process has an extensive range of applications due to its advantages over the traditionally used stamping techniques developed in the past. To enhance the mechanical properties of the indirectly hot-stamped parts, the quenching and partitioning (Q&P) process has been recently applied on boron-alloyed steel. In the current research, it was observed that the tempering treatment on the directly hot-stamped boron steel resulted in better mechanical properties and higher formability index compared with the reported results using the Q&P process. The nano-carbide formation and the dislocation annihilation during the tempering treatment were suggested as the evident reasons for the occurrence of the mentioned robust properties. The ease of the practical implementation of the tempering route together with the markedly enhanced mechanical properties of the tempered parts make the suggested method privileged. Additionally, the variations in the yield strength before and after tempering were quantitatively evaluated.

The effect of the die radius profile accuracy on wear in sheet metal stamping

Abstract: This paper investigates the influence of the die corner radius shape on wear behavior during sheet metal stamping. In particular, small and localized changes from an ideal circular die profile shape were examined and the effect on tool life determined. A novel technique to test and characterize the die profile shape and wear behavior, based on a semi-industrial channel forming process, is presented. It will be shown experimentally that small changes in die radius profile shape (of less than 15 μm) can result in significantly reduced tool life. In all cases examined, the small variations in shape were the result of inherent variations associated with the machining, grinding and polishing processes typically used to manufacture stamping dies and die corner inserts. Numerical simulation shows that these small shape ‘defects’ at the die corner radius can result in a significant increase in local contact pressures, explaining the large adverse changes in tool life. These results are of direct importance to stamping engineers and tool designers and indicate that careful control over die manufacture and maintenance procedures may result in significant improvements in tool life.

Experimental Characterization of Heat Transfer Coefficients During Hot Forming Die Quenching of Boron Steel

Abstract: The heat transfer coefficient (HTC) between the sheet metal and the cold tool is required to predict the final microstructure and mechanical properties of parts manufactured via hot forming die quenching Temperature data obtained from hot stamping experiments conducted on boron steel blanks were processed using an inverse heat conduction algorithm to calculate heat fluxes and temperatures at the blank/die interface The effect of the thermocouple response time on the calculated heat flux was compensated by minimizing the heat imbalance between the blank and the die Peak HTCs obtained at the end of the stamping phase match steady-state model predictions At higher blank temperatures, the time-dependent deformation of contact asperities is associated with a transient regime in which calculated HTCs are a function of the initial stamping temperature

Numerical and Experimental Study of Frictional Behavior in Bending Under Tension Test

Abstract: This paper presents the results of frictional resistance research for three different types of sheet metals, namely from steel, brass and aluminum alloy. The research on friction behavior of these alloys was carried out by using bending under tension test. The influence of the amount of plastic deformation on friction coefficient value was investigated in dry and lubrication conditions. The material data of the sheet metals were determined from the tensile tests. Numerical simulations using finite element method in MSC.Marc 2007r1 computer program are conducted by taking into account the strain hardening phenomenon of the sheet metals. The results show that there are minor differences between the experimental and numerical results. This may be due to the simplification where isotropic material properties are assumed and influences of structural defects are not accounted for in the numerical model.

Automated welding of moulds and stamping tools

Abstract: A tool welding system is disclosed that includes a table that heats a tool. A multi-axis robot includes a welding head that is moved relative to the table in response to a command. A controller is in communication with the robot and generates the command in response to welding parameters. The weld parameters are based upon a difference between an initial tool shape and a desired tool shape. The difference between the initial tool shape and the desired tool shape corresponds to a desired weld shape. The desired weld shape is adjusted based upon initial tool shape variations, which includes thermal growth of the tool. The tool is welded to provide the desired weld shape to achieve a desired tool shape.

Fabrication of micro-channel arrays on thin stainless steel sheets for proton exchange membrane fuel cells using micro-stamping technology

Abstract: Bipolar plates are one of the crucial components of proton exchange membrane fuel cells. Because of the expensive production costs of traditional graphite bipolar plates, which require a few millimeters thickness over the space, the resulting metal bipolar plate reduces the cost, and the thickness can be reduced to the micron range. This study explored the application of micro-stamping technology to produce thin metal bipolar plates with the relevant process parameters. In this study, the channel design was 0.8 ×0.75 mm for the use of a rigid punch on a 50-μm-thick stainless steel sheet (SUS 304) for micro-channel stamping processes. The finite element method and the experimental results were used to analyze the main parameters of the micro-stamping process. The traditional material model and the scale factor modified material model were used for simulation. The experimental results verified that the modified material model is more realistic for products and has superior similarity because the punch load is relatively small. This study used updated Lagrangian formulation concept to establish an elastic–plastic deformation finite element analysis model and scale factor to modify the calculation to effectively simulate the micro-stamping process for metal bipolar plates.

Workpiece stamping intelligent control process and intelligent control manipulator

Abstract: The invention discloses a workpiece stamping intelligent control process. The workpiece stamping intelligent control process controls automatically and satisfies all actions to be operated coherently to effectively improve working efficiency, no manual work is needed, safety is improved and cost is effectively saved. Product quality is guaranteed to enable products to meet market demands. The invention further provides an intelligent control manipulator implementing the process. Through an efficient, accurate, flexible, safe operation mode flexible in design, the intelligent control manipulator is convenient to operate, production efficiency is greatly improved, structural design is reasonable, design mode is flexible, effects are obvious, process persistence is high, raw materials are saved and energy consumption is quite low; a regulation and control type industrial control process satisfies different demands, the structural design enhances smoothness, swing precision is guaranteed, and machining process is guaranteed to be completed automatically, continuously and effectively; and conventional manual or semi-automatic machining modes are replaced, and resources are saved.

Hot stamping foil applied to overlapping hot stamping on gold stamping layer and preparation method of hot stamping foil

Abstract: The invention discloses a hot stamping foil applied to overlapping hot stamping on a gold stamping layer and a preparation method of the hot stamping foil. When overlapping hot stamping is carried out on an existing hot stamping foil, the defects that the transferring is incomplete, the hot stamping is not carried out on some portions due to omission, scumming is caused, powder falls off, and the edge of a hot stamping layer is not clear can happen. The hot stamping foil is composed of a base membrane layer, a release layer, a color coating layer, a vacuum aluminum coated layer and a gumming layer. The gumming layer is prepared by raw materials which comprise, by weight, 1-6 parts of chloroethylene-vinyl acetate resin, 1-10 parts of polyvinyl alcohol, 1-10 parts of acrylic ester, 1-5 parts of nitrocellulose, 1-5 parts of fumed silica, 20-70 parts of ethyl acetate, 10-50 parts of ethyl alcohol and 1-5 parts of propyl acetate. According to the hot stamping foil applied to the overlapping hot stamping on the gold stamping layer, the hot stamping foil has the good stamping performance and the good trimming performance, the overlapping hot stamping layer is complete in transferring, the edge is smooth and free of burrs, the adhesion is firm, the phenomena of dusting, powder falling and the like do not exist, the hot stamping effect is strong in third dimension, and the anti-fake performance is more outstanding.

Car body aluminum alloy plate and manufacturing method thereof

Abstract: The invention provides a high-strength brake hardening car body aluminum alloy plate and a manufacturing method thereof, and belongs to the technical field of aluminum alloy. The aluminum alloy has the component characteristic that a Zn element is added on the basis of the conventional AL-Mg-Si-Cu quaternary alloy, so that the alloy has higher brake hardening performance; and interaction, strengthening-phase separation process and the like among solute elements are reasonably adjusted through reasonable pre-ageing process optimization control, and therefore, a novel car material Al-Mg-Si-Cu-Zn quinary aluminum alloy with excellent comprehensive performances is successfully developed. By adding the element Zn, the aluminum alloy material disclosed by the invention has the performance characteristic of being low in yield strength, good in plasticity and conductive to stamping and forming a car covering piece before baking finish; and after baking finish is finished, the yield strength is greatly improved, the tensile strength is high and the bake hardening performances are high.

Inverted type punching and blanking compound die

Abstract: The utility model discloses an inverted type punching and blanking compound die, and relates to a stamping die. The inverted type punching and blanking compound die comprises an upper die base, a lower die base, a die shank, a guide sleeve and a guide post, wherein a punch-die is arranged on the upper surface of the lower die base; a punching hole is formed in the punch-die; the punch-die is sleeved with an unloading plate; the unloading plate is connected with the lower die base movably through an unloading screw; an unloading spring is arranged between the unloading plate and the lower die base; a blanking female die is arranged on the lower surface of the upper die base; a female die hole is formed in the lower surface of the blanking female die and corresponds to the punch-die; a punching male die matched with the punching hole is arranged inside the female die hole; and a part jacking device is arranged on the punching male die. According to the utility model, blanking and punching for one workpiece can be achieved in one set of dies, so that the production efficiency is improved, the workpiece is avoided from being positioned repeatedly, the product accuracy is improved, and the compound die is very practical.

Hard tinned sheet steel and its production method

Abstract: The invention relates to a hard tinned sheet steel produced from low carbon aluminium killed steel so as to solve the technical problems of easy appearance of local edge waves during current pickling rolling production of tinned sheet steel, high incidence of surface iron oxide scale during continuous annealing production, high yield ratio of tin plates, undesirable stamping processing and the like. The hard tinned sheet steel and its raw sheet comprise the following chemical components (by weight): 0.05-0.07% of C, less than or equal to 0.1% of Si, 0.20-0.30% of Mn, less than or equal to 0.020% of P, less than or equal to 0.020% of S, 0.010-0.060% of Alt, less than or equal to 0.0060% of N, and the balance Fe and some inevitable impurity elements. The production method of the hard tinned sheet steel includes: steelmaking, continuous casting, hot rolling, combined pickling rolling, continuous annealing, double-stand tempering, and electrotinning. The hard tinned sheet steel produced in the invention has the advantages of small production control difficulty, excellent appearance quality, thin specification, stable hardness, and good stamping processing performance, etc., can meet the use requirements of high-speed canning, and can be widely used as a food cans, beverage cans, aerosol cans and other packaging materials.

Metal-stamping die manufactured by additive manufacturing

Abstract: A metal-stamping die or tool is provided. Another aspect uses an additive manufacturing machine and material to create a die. A further aspect provides a method of making a die from an additive manufacturing process and/or using such a die to stamp a metal part, such as a fastener or clip.

Horn basin stand stamping progressive die

Abstract: The utility model discloses a horn basin stand stamping progressive die which comprises an upper die base, a lower die base and a die handle and further comprises a deep drawing forming blanking composite die body and a composite punching die body. The composite punching die body comprises a central hole punching convex die body, a rectangular hole punching convex die body and a punching concave die body, wherein the central hole punching convex die body and the rectangular hole punching convex die body are connected with the upper die base through a convex die fixing plate. The deep drawing forming blanking composite die body comprises a forming concave die body, a blanking concave die body and a deep drawing forming convex die body, wherein the blanking concave die body is directly fixed on the upper die base, a discharging rubber block and a limiting gasket are arranged between the forming concave die body and the upper die base in a padding mode, and the deep drawing forming convex die body and the punching concave die body are fixed on the lower die base. After stamping of a workpiece is carried out by the application of the horn basin stand stamping progressive die, the quality of the workpiece is ensured, and meanwhile the machining efficiency of the workpiece is further effectively improved.

Effect of stamping load variation on deformation behaviour of stainless steel thin plate with microchannel

Abstract: A thin plate like a bipolar plate for a proton exchange membrane fuel cell is one of the core parts for improving the power density in a fuel cell. Stainless steel has excellent characteristics in terms of electrical resistivity, density, and thermal conductivity. Furthermore, stainless steel, instead of graphite, is used as a bipolar plate because it is cheaper and easier to machine. Therefore, in this study, a stainless steel alloy is selected as the ideal material for a bipolar plate. In this article, the results of feasibility experiments are presented; these experiments are performed with the aim of developing fuel cells using stainless steel bipolar plates with multiple channels. In this investigation, a dynamic load was applied, and the formability of microchannels was estimated with different punch pressures and die roundness, using a thin sheet metal of SUS304 with thicknesses of 0.3 and 0.1 mm. In the case of the die roundness of 0.1 mm, the formability is optimized with a sine wave dynamic load...

Formability behaviors of 2A12 thin-wall part based on DYNAFORM and stamping experiment

Abstract: A method integrating theoretical analysis, numerical simulation and experimental methods was adopted to solve the existing problems, including fillet less-plumping, cracks and wrinkling, in the forming process of a double curvature, thin-wall aluminum alloy part (DCTAP) of the aircraft skin. The mechanical properties of a 0.5 mm thick aluminum alloy sheet (2A12) were obtained through the uniaxial tensile test. The optimal blank holder force (BHF), blank shape (BS) and blank dimension (BD) were obtained by simulation using DYNAFORM. A stamping die was fabricated for experiment validation. The experimental results obtained by the coordinate grid strain analysis technology (CGSAT) agreed well with the simulation results, which demonstrated that the method presented here conduced to improving the formability of DCTAP.

Automatic stamping production line for electric appliance casings

Abstract: The invention relates to an automatic stamping production line for electric appliance casings. As casing parts need to be stamping/stretching-molded by multiple procedures in the existing electric appliance industry, different stamping/stretching presses are needed. Meanwhile, a large quantity of assisting labor is needed for transport, locating and the like among the procedures, so that the existing electric appliance industry also has the defects of large worker labor intensity, low safety coefficient and low efficiency. According to the automatic production line provided by the invention, four numerical-controlled stamping/stretching hydraulic machines are used for the stamping/stretching molding of casing sheets, off-line blanks are conveyed to a centering table one by one to be located after being detached by a set of disassembling and stacking manipulators, the blanks on the centering table are conveyed into a press one by one by a feeding manipulator to be stamped/stretched, the stamped/stretched blanks are taken out by a next feeding manipulator, conveyed to a next centering table to be located, sent to a next press and pressed into products, and the finished products are finally conveyed to an output machine by a discharging manipulator. The provided automatic stamping production line for the electric appliance casings is fully novel, can meet the technical requirements of electric appliance casing production and has the advantages of compact structure, simplicity in operation and convenience in maintenance.

Estimation model for magnetic properties of stamped electrical steel sheet

Abstract: Less deterioration in the magnetic properties of electrical steel sheets in the process of stamping out the iron core is necessary in order to maintain performance. First, the influence of plastic strain and stress on the magnetic properties is studied using test pieces, in which plastic strain is added uniformly and residual stress is not induced. Because the influence of plastic strain is expressed using the equivalent plastic strain, at each equivalent plastic strain state the influence of the load stress is investigated. Second, the elastic limit is determined to be about 60% of the macroscopic yield point (MYP), and this agrees with the stress limit inducing irreversible deterioration in the magnetic properties. Therefore, simulation models, in which excess elastic limit plastic deformation begins and the magnetic properties deteriorate sharply, are proposed. Additional points taken into consideration in the deformation analysis are the strain rate sensitivity of flow stress, the anisotropy under deformation, and the influence of stress triaxiality on fracture. Finally, the proposed models are shown to be valid because the magnetic properties of rectangular sheets 5 mm wide stamped out from a nonoriented electrical steel sheet (35A250 JIS grade) can be estimated with good accuracy. It is concluded that the elastic limit must be taken into account in both the stamping process simulation and magnetic field calculation. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 183(2): 1–11, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22269