Showing papers on "Stamping published in 2015"

Thermomechanical analysis, modelling and simulation of the forming of pre-impregnated thermoplastics composites

Abstract: In this paper, the viscoelastic behaviours of pre-impregnated (prepreg) thermoplastic composites are analysed using the bias-extension test. A new constitutive model is proposed in order to simulate the forming of thermoplastic composite prepregs at the macroscopic scale. The model is based on a continuous approach. Hyperelastic behaviours are associated with dry reinforcements. Four principal deformation modes, all considered independent, define the hyperelastic potential: the elongation in warp direction, the elongation in weft direction, the in-plane shear strain and the bending contribution. Experience shows that viscoelastic behaviour is mainly associated with the in-plane shear deformation. A non-linear visco-hyperelastic model based on the generalisation of Maxwell rheological model is considered for this type of deformation mode. The finite element simulation of a stamping case using this model is introduced. The influence of temperature on the forming stage and the performance of the model are evaluated.

Tribology in metal forming at elevated temperatures

Abstract: The tribo-characteristics of metal forming at high temperatures have not yet been well understood due to the complex nature of thermal, microstructural, interaction, and process parameters. This is a review paper on the effects of temperature, coating, and lubrication to the tribological characteristics in hot forming as well as the tribometers for different metal forming processes at elevated temperatures mainly based on the experimental work. The tribological behaviors of oxides in hot forming, such as rolling and stamping, were reviewed and presented. Some commonly used surface coatings and lubricants in hot forming were given. Many types of tribometer were selected and presented and some of them provided a great potential to characterize friction and wear at elevated temperatures. Nevertheless, more testing conditions should be further investigated by developing new tribometers. Eventually, experimental results obtained from reliable tribometers could be used in theory and model developments for different forming processes and materials at high temperatures. The review also showed the great potential in further investigations and innovation in tribology.

Influence of process parameters on the thermostamping of a [0/90]12 carbon/polyether ether ketone laminate

Abstract: In this study, an experimental evaluation of the thermostamping process was made for a 3D part molded with a [0/90] 12 laminate composed of unidirectional carbon fiber/polyether ether ketone (CF/PEEK) plies. Using the Taguchi method, the effect of four operational parameters on the part thickness, interlaminar shear strength and the degree of crystallinity were investigated. These parameters are the preheating temperature in the oven, the mold temperature, the oven to mold transfer time and the stamping pressure. The results show that the mold temperature and stamping pressure have a significant effect on part consolidation. In addition, the interlaminar shear strength, measured at the base of the molded part, was higher for thinner parts compared to those having a greater thickness. These results were also confirmed by Differential Scanning Calorimetry analysis, which show that the degree of crystallinity is higher for thinner parts.

Processing method of metal middle frame mobile phone shell structure

Abstract: The invention discloses a processing method of a metal middle frame mobile phone shell structure and relates to the technical field of processing of mobile phones. The processing method comprises the following steps: A, stamping a blank of the metal middle frame by using a metal plate; B, milling an auxiliary antenna area on the blank of the metal middle frame in a CNC manner and retaining a connection position; C, forming a metal bottom shell by using an aluminum die casting manner; D, connecting the blank of the metal middle frame with the metal bottom shell to be a whole body; E, forming a main antenna area on the blank of the metal middle frame by using an injection molding manner; and F, milling off the connection position on the blank of the metal middle frame in the CNC manner to obtain the metal middle frame mobile phone shell structure. By combining processes of stamping molding, injection molding and CNC processing, the metal middle frame mobile phone shell structure is processed; the metal middle frame mobile phone shell structure is stable in process, high in production efficiency, short in processing time and low in production cost.

Sheet metal forming using FDM rapid prototype tool

Abstract: Purpose – The purpose of this paper is to investigate usage of fused deposition modeling (FDM)-based sheet metal tooling for small lot productions as a real case. FDM-based sheet metal tooling was used for stamping prototype parts for two different materials to evaluate dimensional conformance. Design/methodology/approach – The experimental process of data capture used the following steps: sheet metal parts were stamped and optically scanned at every 10th interval for both DC04 and S355MC material. FDM-based upper and lower dies were optically scanned at 1st, 51st and 101st intervals. Dimensional conformance analyses were carried out by using scanned data to evaluate the behavior of FDM dies against DC04 and S355MC materials in terms of geometric deviation. Findings – Satisfactory results were obtained for DC04 material by using FDM-based tooling, and overall deviation was at an acceptable level in terms of production tolerance. S355MC material is harder than DC04 and results were not convenient in terms ...

Water-based high-corrosion-resistance coating with excellent stamping performance and preparing method and application of water-based high-corrosion-resistance coating

Abstract: The invention belongs to the technical field of surface corrosion prevention and discloses a water-based high-corrosion-resistance coating with excellent stamping performance and a preparing method and application of the water-based high-corrosion-resistance coating. The coating comprises, by mass, 25-60 parts of water-based resin, 2-8 parts of water-based cross-linking agent, 0.1-0.5 part of catalyst, 4-10 parts of cosolvent, 0.1-1 part of flatting agent, 0.1-10 parts of lubricating agent, 2-10 parts of water-based toughening resin, 0.1-0.5 part of defoaming agent, 0.5-3 parts of thickening agent and the balance water, and the total mass parts of the components are 100 parts. According to the water-based high-corrosion-resistance coating, the water-base resin serves as film forming matter, so that good construction performance is achieved, curing is quick, super corrosion resistance can be obtained when the thickness of the coating is 2-5 micrometers, the performance of resisting neutral salt mist is longer than 2,000 hours, resistance to acid salt mist is longer than 500 h, the corrosion grade can reach 9.8 or higher, and the salt mist resisting performance of the coating is maintained unchanged after stamping or bending is carried out.

High-Speed Friction-Stir Welding to Enable Aluminum Tailor-Welded Blanks

Abstract: Current welding technologies for production of aluminum tailor-welded blanks (TWBs) are utilized in low-volume and niche applications, and they have yet to be scaled for the high-volume vehicle market. This study targeted further weight reduction, part reduction, and cost savings by enabling tailor-welded blank technology for aluminum alloys at high volumes. While friction-stir welding (FSW) has been traditionally applied at linear velocities less than 1 m/min, high-volume production applications demand the process be extended to higher velocities more amenable to cost-sensitive production environments. Unfortunately, weld parameters and performance developed and characterized at low-to-moderate welding velocities do not directly translate to high-speed linear FSW. Therefore, to facilitate production of high-volume aluminum FSW components, parameters were developed with a minimum welding velocity of 3 m/min. With an emphasis on weld quality, welded blanks were evaluated for postweld formability using a combination of numerical and experimental methods. An evaluation across scales was ultimately validated by stamping full-size production door inner panels made from dissimilar thickness aluminum TWBs, which provided validation of the numerical and experimental analysis of laboratory-scale tests.

Steel plate for hot stamping, hot stamping process and hot-stamped member

Abstract: The invention relates to a steel plate for hot stamping, a hot stamping process and a hot-stamped member. The steel plate for hot stamping is characterized by comprising, by weight, 0.18 to 0.42% of C, 4 to 8.5% of Mn and 0.8 to 3.0% of Si and Al, with the balance being Fe and avoidable impurities, wherein the alloy component of the steel plate satisfy the condition that the actual measured value of martensite phase transformation beginning temperature is no more than 280 DEG C. A manufacturing method for the hot-stamped member comprises the following steps: heating a material to 700 to 850 DEG C and carrying out stamping; then carrying out cooling in a die or air cooling or cooling in other manners to 150 to 260 DEG C below the martensite phase transformation beginning temperature; and heating the stamped member to 160 to 450 DEG C, maintaining the temperature for 1 to 100,000 s, carrying out tempering heat treatment and cooling the stamped member to room temperature. The hot-stamped member prepared in the invention has yield strength of no less than 1200 MPa, tensile strength of no less than 1600 MPa and total elongation percentage of no less than 10%.

Shell metal stamping part surface treatment technique

Abstract: The invention discloses a shell metal stamping part surface treatment technique which comprises the following steps: 1) mixing 65 parts by mass of ethanedioic acid, 7 parts by mass of zinc nitrate, 5 parts by mass of sodium molybdate, 2.3 parts by mass of nickel nitrate, 2 parts by mass of coconut diethanol amide, 3 parts by mass of phytic acid and 2 parts by mass of dodecyl trimethyl ammonium sulfate, and reacting at 115 DEG C for 3 hours to obtain a metal surface treating agent; 2) mixing 17 parts by mass of metal surface treating agent and 136 parts by mass of water to obtain a surface treatment working fluid; and 3) heating the surface treatment working fluid to 54 DEG C, and putting the metal stamping part in the surface treatment working fluid to perform surface treatment for 27 minutes. The surface treatment technique can enhance the oxidation resistance and corrosion resistance of the metal stamping part.

Surface treatment technique for metal stamping part

Abstract: The invention discloses a surface treatment technique for a metal stamping part, which comprises the following steps: 1) mixing 53 parts by mass of succinic acid, 5 parts by mass of zinc nitrate, 6 parts by mass of sodium molybdate, 28 parts by mass of nickel nitrate, 5 parts by mass of sodium bifluoride, 4 parts by mass of polysiloxane polyether copolymer and 4 parts by mass of alkyl trimethyl ammonium methylsulfate, and reacting at 112 DEG C for 45 hours to obtain a metal surface treating agent; 2) mixing 13 parts by mass of metal surface treating agent with 128 parts by mass of water to obtain a surface treatment working fluid; and 3) heating the surface treatment working fluid to 57 DEG C, and immersing the metal stamping part in the surface treatment working fluid for 30 minutes The surface treatment technique can enhance the oxidation resistance and corrosion resistance of the metal stamping part

A new process of forming metallic bipolar plates for PEM fuel cell with pin-type pattern

Abstract: Bipolar plates are the most important and expensive components of a fuel cell. These plates can be fabricated by different processes, such as machining graphite plates, producing composite materials, and forming metallic sheets. Due to some benefits of the metallic plates, especially with stainless steel sheets, they have recently been more noticeable. There are various flow field patterns with different applications in these plates, being classified into simple and complex ones in forming process for spiral or parallel and multi-array pin-type examples, respectively. In this study, hydroforming, stamping, and hybrid hydroforming–stamping methods have been used to investigate the forming capability of multi-array pin-type pattern, and, consequently, to compare the results of filling percentage and thickness distribution of these methods. According to the results, samples formed by the hybrid method have shown desirable filling percentage and thickness distribution. The effect of preload pressure of this method on thickness distribution has subsequently been studied and it was observed that the thickness distribution of the formed sample was enhanced by maximizing the pressure of the hydroforming stage.

Stamping Plant 4.0 – Basics for the Application of Data Mining Methods in Manufacturing Car Body Parts

Abstract: Data-driven quality evaluation in the stamping process of car body parts is quite promising because dependencies in the process have not yet been sufficiently researched. However, the application of data mining methods for the process in stamping plants would require a large number of sample data sets. Today, acquiring these data represents a major challenge, because the necessary data are inadequately measured, recorded or stored. Thus, the preconditions for the sample data acquisition must first be created before being able to investigate any correlations. In addition, the process conditions change over time due to wear mechanisms. Therefore, the results do not remain valid and a constant data acquisition is required. In this publication, the current situation in stamping plants regarding the process robustness will be first discussed and the need for data-driven methods will be shown. Subsequently, the state of technology regarding the possibility of collecting the sample data sets for quality analysis in producing car body parts will be researched. At the end of this work, an overview will be provided concerning how this data collection was implemented at BMW as well as what kind of potential can be expected.

Plastic crushing machine

Abstract: The invention discloses a plastic crushing machine. The crushing machine comprises a shell (5), a stamping mechanism, a crushing mechanism, a screening mechanism and a motor (6). The stamping mechanism is located on the top of the shell (5). The crushing mechanism is arranged in the middle of the shell (5). The screening mechanism is located below the crushing mechanism. The motor (6) is connected with the crushing mechanism through a conveying belt. Due to the fact that the stamping mechanism and the screening mechanism are arranged inside the crushing machine, the crushing effect of the crushing machine is effectively improved, and meanwhile the problem that a screen mesh inside the crushing machine is prone to being blocked is solved.

Incremental Metal Forming Processes in Manufacturing

Abstract: Incremental sheet metal forming (ISMF) has demonstrated its great potential to form complex three-dimensional parts without using component-specific tools against the conventional stamping operation. Forming components without component-specific tooling in ISMF provides a competitive alternative for economically and effectively fabricating low-volume functional sheet metal products; hence, it offers a valid manufacturing process to match the need of mass customization, which is regarded as the future of manufacturing. In ISMF process, sheet is clamped in a fixture/frame with an opening window on a programmable machine, and a hemispherical/spherical ended tool is programmed to move in a predefined path giving shape to the clamped sheet by progressively deforming a small region in incremental steps. Although formability in incremental forming is higher than that of conventional forming, the capability to form components with desired accuracy and surface finish without fracture becomes an important requirement for commercializing the ISMF processes. This chapter presents various configurations developed to incrementally form the sheet metal components, experimental as well as numerical methods for estimating forming limits, procedures for enhancing the accuracy, and methodologies for tool path generation.

Fork stamping of pristine carbon nanotubes onto ferromagnetic contacts for spin-valve devices

Abstract: We present a fabrication scheme called 'fork stamping' optimized for the dry transfer of individual pristine carbon nano- tubes (CNTs) onto ferromagnetic contact electrodes fabricated by standard lithography. We demonstrate the detailed recipes for a residue-free device fabrication and in-situ current annealing on suspended CNT spin-valve devices with ferromagnetic Permalloy (Py) contacts and report preliminary transport characterization and magnetoresistance experiments at cryogenic temperatures. This scheme can directly be used to implement more complex device structures, including multiple gates or superconducting contacts.

Automatic feeding stamping equipment

Abstract: The invention discloses automatic feeding stamping equipment. The automatic feeding stamping equipment comprises a stamping machine tool and a placing frame, material sheets to be stamped are stacked on the placing frame, a pushing device for sequentially pushing out the material sheets from the underneath is arranged below the placing frame, a rotary feeding device is arranged between the stamping machine tool and the pushing device, and the rotary feeding device takes the pushed material sheets out of the pushing device and conveys the material sheets to a stamping platform of the stamping machine tool. The automatic feeding stamping equipment is high in automation degree, a worker does not need to place the material sheets one by one, time is saved, operation is fast, the labor intensity of the worker is greatly relieved, the working efficiency is improved, and the automatic feeding stamping equipment is safe, reliable and beneficial for mass production.

Highly hydrophobic hierarchical nanomicro roughness polymer surface created by stamping and laser micromachining

Abstract: This article describes the design and fabrication of hierarchical nanomicrostructured polymer surfaces with high hydrophobicity. The nanoscale roughness is achieved by stamping a ZnO nanowire film into PDMS. Subsequently, microstructures with different periodicities are created in the stamped PDMS sample by direct laser writing using femtosecond pulses. With this approach, we were able to produce hierarchical surface morphologies, composed of nano and microscale structures that exhibit water contact angles larger than 160 degrees.

Hot stamping method for performance gradient distribution of high-strength steel parts

Abstract: The invention relates to a hot stamping method for performance gradient distribution of high-strength steel parts. The hot stamping method comprises the following steps: locally and quickly cooling homogenized sheets heated to reach austenitization to a certain temperature (cooling to be below Ms point within 1 to 30s) and quenching; feeding the sheets with non-uniform temperature into another furnace for heating at the temperature of 600 to 1,000DEG C for 0.5 to 10min; after heating, obtaining structures in a low-strength area, namely ferrites, tempered martensiteas and austenites of certain amounts, and obtaining microstructures in the high-strength area, which are still complete austenitizing structures; transferring the sheets with different microstructures into a die with cooling water for stamping, and finally obtaining hot stamping forming parts with different mechanical properties.

An audio signal based model for condition monitoring of sheet metal stamping process

Abstract: Tool condition monitoring is an important factor in ensuring manufacturing efficiency and product quality. Audio signal based methods are a promising technique for condition monitoring. However, the influence of interfering signals and background noise has hindered the use of this technique in production sites. Blind signal separation (BSS) has the potential to solve this problem by recovering the signal of interest out of the observed mixtures, given that the knowledge about the BSS model is available. In this paper, we discuss the development of the BSS model for sheet metal stamping with a mechanical press system, so that the BSS techniques based on this model can be developed in future. This involves conducting a set of specially designed machine operations and developing a novel signal extraction technique. Also, the link between stamping process conditions and the extracted audio signal associated with stamping was successfully demonstrated by conducting a series of trials with different lubrication conditions and levels of tool wear.

Method for forming metal mobile phone shells

Abstract: The invention discloses a method for forming metal mobile phone shells, and relates to the technical field of mobile phones. The method for forming the metal mobile phone shells includes stamping and bending metal plates to obtain integral outlines of the integrated mobile phone shells so as to obtain initial blank products; carrying out CNC (computer numerical control) machining on the initial blank products to obtain semi-finished products of the metal mobile phone shells; carrying out post-processing on the semi-finished products of the metal mobile phone shells to obtain the metal mobile phone shells. Arc structures are arranged between the side walls and the bottom walls of the integral outlines of the integrated mobile phone shells. CNC machining procedures include (1), milling off burrs on redundant thickness-size sides of the bottom walls and the side walls of the initial blank products under the CNC; (2), inwardly milling the outer walls of arc corners between the side walls and the bottom walls of the initial blank products under the CNC to obtain step structures and respectively forming C-angle edges at the step structures; (3), finely milling the C-angle edges of the step structures under the CNC. The C-angle edges are close to the bottom walls and the side walls of the initial blank products. The method has the advantages that a stamping forming procedure and a CNC machining procedure are combined with each other, so that the metal mobile phone shells can be formed, and the method is stable in process, high in machining precision and production efficiency, short in machining elapsed time and low in production cost.

Automatic lathe of car baffle punching press

Abstract: The utility model discloses an automatic lathe of car baffle punching press, including pushing away material cylinder, scraping wings, punching press frame, stamping die, input transfer area and output transfer area, the punching machine shelf location has stamping die, and the punching press cylinder is connected through the telescopic link in the stamping die top, is equipped with the punching press platform below the stamping die, the input frame has been placed in the dead ahead of punching press platform, and the input transfer area is installed at input frame top, the output frame has been placed to one side of punching press platform, and the output transfer area is installed at output frame top, the opposite side level of punching press platform is fixed with and pushes away the material cylinder, pushes away material cylinder front end connection scraping wings, a ram efficiency need not manually operation, has stopped the potential safety hazard that automatic lathe of car baffle punching press, simple structure, the operation is stable, realizes the automatic punching press of work piece, has alleviateed ejection of compact operation personnel's intensity of labour, has improved the work piece.

Mass scaling and stable time step estimates for isogeometric analysis

Abstract: Summary Metal stamping is one of the most cost effective manufacturing methods for producing precision parts. The precision of the parts is a function of the uniformity of the material used for the blank and the design of the dies. During the metal stamping process, the blank undergoes large, inelastic deformations, and once it is removed from the dies, springs back to a shape different from the die. This spring back must be accounted for in the design of the die, and its prediction is a major challenge in computational mechanics. Isogeometric analysis, which uses the same basis functions as the computer-aided design programs used to design the shape of the part, is an attractive alternative to traditional finite element analysis for metal stamping. Mass scaling, and the underlying stable time step estimates, that are commonly used in metal stamping simulations are presented for isogeometric analysis. Example calculations are presented to demonstrate the effectiveness of isogeometric analysis in metal stamping. Copyright © 2014 John Wiley & Sons, Ltd.

Surface treatment process for radiator shell metal stamping piece

Abstract: The invention discloses a surface treatment process for a radiator shell metal stamping piece. The surface treatment process comprises the following steps: 1) mixing 15 parts by mass of benzoic acid, 8 parts by mass of polyoxyethylene sorbitan fatty acid ester, 2 parts by mass of sodium molybdate, 4 parts by mass of nickel nitrate, 4 parts by mass of sodium hydrogenfluoride, 2 parts by mass of phytic acid and 3.6 parts by mass of hydroxypropyl methyl cellulose, and reacting for 3.5 hours at 110 DEG C to obtain a metal surface treatment agent; 2) mixing 13 parts by mass of metal surface treatment agent and 96 parts by mass of water to obtain a surface treatment working solution; and 3) heating the surface treatment working solution to 50 DEG C, and putting the metal stamping piece into the surface treatment working solution for 25 minutes. The surface treatment process for the radiator shell metal stamping piece can improve the oxidation resistance and corrosion resistance of the metal stamping piece.