Stamping (metalworking)

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Animation of a power press with a fixed barrier guard Power press animation.gif
Animation of a power press with a fixed barrier guard

Stamping (also known as pressing) is the process of placing flat sheet metal in either blank or coil form into a stamping press where a tool and die surface forms the metal into a net shape. Stamping includes a variety of sheet-metal forming manufacturing processes, such as punching using a machine press or stamping press, blanking, embossing, bending, flanging, and coining. [1] This could be a single stage operation where every stroke of the press produces the desired form on the sheet metal part, or could occur through a series of stages.

Contents

The process is usually carried out on sheet metal, but can also be used on other materials, such as polystyrene. Progressive dies are commonly fed from a coil of steel, coil reel for unwinding of coil to a straightener to level the coil and then into a feeder which advances the material into the press and die at a predetermined feed length. Depending on part complexity, the number of stations in the die can be determined.

Stamping is usually done on cold metal sheet. See Forging for hot metal forming operations.

History

It is believed that the first coins were struck by the Lydians in what is modern-day Turkey in the seventh century B.C. Until 1550, the hammering method of coins remained the primary method of coin-making. Marx Schwab in Germany developed a new process for stamping that involved as many as 12 men turning a large wheel to press metal into coins. In the 1880s, the stamping process was further innovated. [2]

Stamped parts were used for mass-produced bicycles in the 1880s. Stamping replaced die forging and machining, resulting in greatly reduced cost. Although not as strong as die forged parts, they were of good enough quality. [3]

Stamped bicycle parts were being imported from Germany to the United States in 1890. U.S. companies then started to have stamping machines custom built by U.S. machine tool makers. Through research and development, Western Wheel was able to stamp most bicycle parts. [4]

Several automobile manufacturers adopted stamping of parts. Henry Ford resisted the recommendations of his engineers to use stamped parts, but when his company could not satisfy demand with die forged parts, Ford was forced to use stamping. [5]

Over the history of metal stamping, forging and deep drawing, presses of all types are the backbone of metals manufacturing. The processes continue to improve in moving more metal in one press stroke. Press and interconnected automation devices increase production rates, reduce labor costs and provide more safety for workers.

Operation

Piercing and cutting can also be performed in stamping presses. Progressive stamping is a combination of the above methods done with a set of dies in a row through which a strip of the material passes one step at a time.

Lubricant

The Tribology process generates friction which requires the use of a lubricant to protect the tool and die surface from scratching or galling. The lubricant also protects the sheet metal and finished part from the same surface abrasion as well as facilitate elastic material flow preventing rips, tears and wrinkles. There are a variety of lubricants available for this task. They include plant and mineral oil-based, animal fat or lard-based, graphite-based, soap and acrylic-based dry films. The newest technology in the industry is polymer-based synthetic lubricants also known as oil-free lubricants or non-oil lubricants. The term "Water-Based" lubricant refers to the larger category that also includes more traditional oil and fat-based compounds.[ citation needed ]

Simulation

Sheet metal forming simulation is a technology that calculates the process of sheet metal stamping, [7] predicting common defects such as splits, wrinkles, springback and material thinning. Also known as forming simulation, the technology is a specific application of non-linear finite element analysis. The technology has many benefits in the manufacturing industry, especially the automotive industry, where lead time to market, cost and lean manufacturing are critical to the success of a company.

Recent research by the Aberdeen research company (October 2006) found that the most effective manufacturers spend more time simulating upfront[ clarification needed ] and reap the rewards towards the end of their projects. [8]

Stamping simulation is used when a sheet metal part designer or toolmaker desires to assess the likelihood of successfully manufacturing a sheet metal part, without the expense of making a physical tool. Stamping simulation allows any sheet metal part forming process to be simulated in the virtual environment of a PC for a fraction of the expense of a physical tryout.

Results from a stamping simulation allow sheet metal part designers to assess alternative designs very quickly to optimize their parts for low cost manufacture.

Microstamping

While the concept of stamping sheet metal components has traditionally focused on the macro level (e.g. vehicle, aircraft, and packaging applications), the continuing trend of miniaturization has driven research into micro- forms of stamping. From the early development of micropunching machines in the early to mid-2000s to the creation and testing of a microbending machine at Northwestern University in the 2010s, microstamping tools continue to be researched as alternatives to machining and chemical etching. Examples of applications of sheet metal microstamping include electrical connectors, micromeshes, microswitches, microcups for electron guns, wristwatch components, handheld device components, and medical devices. However, key issues such as quality control, high-volume application, and the need for material research into mechanical properties must be addressed before full-scale implementation of the technology is realized. [9] [10] [11]

Industry-specific applications

Metal stamping can be applied to a variety of materials based on their unique metalworking qualities for a number of applications across a wide range of industries. Metal stamping may require the forming and processing of base common metals to rare alloys for their application-specific advantages. Some industries require the electrical or thermal conductivity of beryllium copper in areas such as aerospace, electrical, and the defense industry, or the high strength application of steel and its many alloys for the automotive industry.

Industries metal stamping is used for:

See also

Footnotes

  1. Kalpakjian, Serope; Schmid, Steven (2001). Manufacturing Engineering and Technology (International edition. 4th ed.). Prentice Hall. ISBN   0-13-017440-8.
  2. says, Jesse Kent (2015-06-26). "Metal Stamping History | Thomas Engineering Company". Thomas Engineering News | Tips. Retrieved 2019-08-15.
  3. Hounshell, David A. (1984), From the American System to Mass Production, 1800–1932: The Development of Manufacturing Technology in the United States, Baltimore, Maryland: Johns Hopkins University Press, ISBN   978-0-8018-2975-8, LCCN   83016269, OCLC   1104810110
  4. Hounshell 1984 , pp. 208–12
  5. Hounshell 1984
  6. Hedrick, Art (December 15, 2009). "Sheet Metal Stamping 101, part V". Fabricators and Manufacturers Association.
  7. "Sheet Metal Stamping".
  8. "The Simulation-driven Design Benchmark Report: Getting It Right the First Time". Aberdeen Group. 2006-10-31. Retrieved 2011-11-07.
  9. Razali, A.R.; Qin, Y. (2013). "A review on micro-manufacturing, micro-forming and their key issues". Procedia Engineering. 53 (2013): 665–672. doi: 10.1016/j.proeng.2013.02.086 .
  10. Dixit, U.S.; Das, R. (15 October 2012). "Chapter 15: Microextrusion". In Jain, V.K. (ed.). Micromanufacturing Processes. CRC Press. pp. 263–282. ISBN   9781439852903.
  11. Advanced Manufacturing Processes Laboratory (2015). "Process Analysis and Variation Control in Micro-stamping". Northwestern University. Retrieved 18 March 2016.

Related Research Articles

A lubricant is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, transporting foreign particles, or heating or cooling the surfaces. The property of reducing friction is known as lubricity.

<span class="mw-page-title-main">Powder metallurgy</span> Process of sintering metal powders

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A die is a specialized machine tool used in manufacturing industries to cut and/or form material to a desired shape or profile. Stamping dies are used with a press, as opposed to drawing dies and casting dies which are not. Like molds, dies are generally customized to the item they are used to create.

<span class="mw-page-title-main">Metal fabrication</span> Creation of metal structures

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<span class="mw-page-title-main">Sheet metal</span> Metal formed into thin, flat pieces

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<span class="mw-page-title-main">Gauge block</span> System for producing precision lengths by stacking components

Gauge blocks are a system for producing precision lengths. The individual gauge block is a metal or ceramic block that has been precision ground and lapped to a specific thickness. Gauge blocks come in sets of blocks with a range of standard lengths. In use, the blocks are stacked to make up a desired length.

<span class="mw-page-title-main">Hydroforming</span> Method of shaping metal through pressurized water

Hydroforming is a cost-effective way of shaping ductile metals such as aluminium, brass, low alloy steel, and stainless steel into lightweight, structurally stiff and strong pieces. One of the largest applications of hydroforming is the automotive industry, which makes use of the complex shapes made possible by hydroforming to produce stronger, lighter, and more rigid unibody structures for vehicles. This technique is particularly popular with the high-end sports car industry and is also frequently employed in the shaping of aluminium tubes for bicycle frames.

<span class="mw-page-title-main">Drawing (manufacturing)</span> Use of tensile forces to elongate a workpiece

Drawing is a manufacturing process that uses tensile forces to elongate metal, glass, or plastic. As the material is drawn (pulled), it stretches and becomes thinner, achieving a desired shape and thickness. Drawing is classified into two types: sheet metal drawing and wire, bar, and tube drawing. Sheet metal drawing is defined as a plastic deformation over a curved axis. For wire, bar, and tube drawing, the starting stock is drawn through a die to reduce its diameter and increase its length. Drawing is usually performed at room temperature, thus classified as a cold working process; however, drawing may also be performed at higher temperatures to hot work large wires, rods, or hollow tubes in order to reduce forces.

<span class="mw-page-title-main">Punching</span> Creating a hole by forcing a tool through the workpiece

Punching is a forming process that uses a punch press to force a tool, called a punch, through the workpiece to create a hole via shearing. Punching is applicable to a wide variety of materials that come in sheet form, including sheet metal, paper, vulcanized fibre and some forms of plastic sheet. The punch often passes through the work into a die. A scrap slug from the hole is deposited into the die in the process. Depending on the material being punched this slug may be recycled and reused or discarded.

<span class="mw-page-title-main">Stamping press</span>

A stamping press is a metalworking machine tool used to shape or cut metal by deforming it with a die. A stamping press uses precision-made male and female dies to shape the final product. It is a modern-day counterpart to the hammer and anvil.

<span class="mw-page-title-main">Deep drawing</span> Metalworking process

Deep drawing is a sheet metal forming process in which a sheet metal blank is radially drawn into a forming die by the mechanical action of a punch. It is thus a shape transformation process with material retention. The process is considered "deep" drawing when the depth of the drawn part exceeds its diameter. This is achieved by redrawing the part through a series of dies.

<span class="mw-page-title-main">Photochemical machining</span> Process that uses chemicals to machine sheet metal

Photochemical machining (PCM), also known as photochemical milling or photo etching, is a chemical milling process used to fabricate sheet metal components using a photoresist and etchants to corrosively machine away selected areas. This process emerged in the 1960s as an offshoot of the printed circuit board industry. Photo etching can produce highly complex parts with very fine detail accurately and economically.

<span class="mw-page-title-main">Blanking and piercing</span> Shearing processes

Blanking and piercing are shearing processes in which a punch and die are used to produce parts from coil or sheet stock. Blanking produces the outside features of the component, while piercing produces internal holes or shapes. The web is created after multiple components have been produced and is considered scrap material. The "slugs" produced by piercing internal features are also considered scrap. The terms "piercing" and "punching" can be used interchangeably.

In manufacturing, threading is the process of creating a screw thread. More screw threads are produced each year than any other machine element. There are many methods of generating threads, including subtractive methods ; deformative or transformative methods ; additive methods ; or combinations thereof.

Cladding is the bonding together of dissimilar metals. It is different from fusion welding or gluing as a method to fasten the metals together. Cladding is often achieved by extruding two metals through a die as well as pressing or rolling sheets together under high pressure.

<span class="mw-page-title-main">Roll forming</span> Continuous bending of a long strip of sheet metal into a desired cross-section

Roll forming, also spelled roll-forming or rollforming, is a type of rolling involving the continuous bending of a long strip of sheet metal into a desired cross-section. The strip passes through sets of rolls mounted on consecutive stands, each set performing only an incremental part of the bend, until the desired cross-section (profile) is obtained. Roll forming is ideal for producing constant-profile parts with long lengths and in large quantities.

<span class="mw-page-title-main">Rotary union</span>

A rotary union is a union that allows for rotation of the united parts. It is thus a device that provides a seal between a stationary supply passage and a rotating part to permit the flow of a fluid into and/or out of the rotating part. Fluids typically used with rotary joints and rotating unions include various heat transfer media and fluid power media such as steam, water, thermal oil, hydraulic fluid, and coolants. A rotary union is sometimes referred to as a rotating union, rotary valve, swivel union,rotorseal, rotary couplings, rotary joint, rotating joints, hydraulic coupling, pneumatic rotary union, through bore rotary union, air rotary union, electrical rotary union, or vacuum rotary union

Today the metal forming industry is making increasing use of simulation to evaluate the performing of dies, processes and blanks prior to building try-out tooling. Finite element analysis (FEA) is the most common method of simulating sheet metal forming operations to determine whether a proposed design will produce parts free of defects such as fracture or wrinkling.

Digital manufacturing is an integrated approach to manufacturing that is centered around a computer system. The transition to digital manufacturing has become more popular with the rise in the quantity and quality of computer systems in manufacturing plants. As more automated tools have become used in manufacturing plants it has become necessary to model, simulate, and analyze all of the machines, tooling, and input materials in order to optimize the manufacturing process. Overall, digital manufacturing can be seen sharing the same goals as computer-integrated manufacturing (CIM), flexible manufacturing, lean manufacturing, and design for manufacturability (DFM). The main difference is that digital manufacturing was evolved for use in the computerized world.

<span class="mw-page-title-main">Hot form quench</span> Aluminium forming technique

Hot Form Quench (HFQ®) - an aluminium hot forming lightweighting technology - is an industrial stamping process for the production of deep drawn, precise and complex geometry ultra-high strength aluminium sheet components. It is the aluminium hot stamping process for age-hardening grades of sheet and has similarities to the press hardening of ultra-high strength steels. HFQ, the original aluminium hot stamping process, exploits viscoplasticity of aluminium at high temperatures to facilitate the production of lightweight structures, often replacing steel, composites, castings, extrusions or multiple cold formed pressings.

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