In the forging process, metal is shaped by pressing, pounding, or squeezing under very high pressure to form parts called forgings. Almost any metal can be forged, including carbon, alloy and stainless steel, aluminum, titanium, brass, copper, and others. The metal is usually preheated prior to the forging services process, but not melted, as in the casting process.
The types of forging services selected are determined by the shape, size and material of the metal to be forged and the end product. There are several different types of forging processes.
1. COLD FORGING
In cold forging, the metal being processed is not directly heated. Instead, it is molded under extreme pressure. This process makes products that are precisely sized to final shape. It is often used to create small components like fasteners. While the forces required to mold the metals are extreme, the overall energy needed to forge items using this process is rather small, as no heating is required. Items prepared through this process are generally strong, as heating has not weakened the strength and consistency of the metal.
2. IMPRESSION DIE FORGING
3. OPEN DIE FORGING
WHY FORGINGS ?
FORGING METALS (Copper, Brass & Bronze Forgings)
Forgings of Copper, Brass and Bronze alloys offer a number of outstanding advantages over parts produced by other manufacturing processes. These advantages result from the inherent properties of copper and copper alloys plus additional improvements in mechanical and physical properties imparted by the forging process. We can offer fully machined forgings, plating, polishing, powder coating, painting, assembly work, design assistance, and much more. Copper, Brass and Bronze forgings offer the designer unique combinations of properties that other metals cannot match. Alloys can be selected to utilize the following unique characteristics :
The forging process and aluminum alloys ensure the best of great strength, light weight and attractive appearance. Aluminum Forgings are generally used in applications where the high integrity of the part is of utmost importance. They are used primarily for structural components such as the intake (front end) of Gas turbine engines where light weight is crucial. In automotive applications, forged components are commonly found at points of shock and stress. Forged automobile components include connecting rods, crankshafts, wheel spindles, axle beams, pistons, gears, and steering arms. Forgings are also used in helicopters, piston-engine planes, commercial jets, and supersonic military aircraft. Many aircraft are “designed around” forgings and contain more than 450 structural forgings as well as hundreds of forged engine parts. “Forged” is the mark of quality in hand tools and hardware. Pliers, hammers, sledgers, wrenches, garden implements, and surgical tools are almost always produced through forging.
The aluminum components manufactured range in weight from a few ounces to a few hundred pounds, and are forged into a wide variety of shapes and sizes with or without cores.
Heat Treating prepare forged aluminum products for secondary machining and assembly. We offer other services such as finish machining, anodizing, painting, powder coating, polishing assembly work, design assistance, etc. A variety of cleaning processes including chemical, vibratory and shot-blast.
STAINLESS AND ALLOY STEEL FORGINGS
Stainless and Alloy Steel forgings are manufactured for use in various environments including offshore and land installations, chemical, petro-chemical, food processing, medical tool & equipment industry, power generation, marine and general engineering. Stainless Steels are used in the low -pressure turbine (hot) section of gas turbines. Alloy Steels are used for various gas turbines components where high strength and wear characteristics are required.
FINISHES AND SECOND PROCESSES
Hard-Coat Anodize on Aluminum
Properties & Advantages
Regular or Conventional Anodize
Properties & Advantages
Hard-coat Anodize coatings may be dyed a variety of colors. However due to its naturally darker appearance, dyeing does not produce the vibrant colors that a Type II sulfuric anodize will. Additionally the required sealing process after dyeing does slightly reduce hardness.
Regular or Conventional Anodize
Chem-Film or Chromate Conversion
Electroless and Electro-Deposited Nickel Plating
Masking and Plugging
Proper masking is critical to high-quality product finishing and painting. Automotive, Military and numerous other industries require masking services. The masking or plugging of parts is sometimes necessary, where dual processes are to be performed. The use of the correct masking and plugging products can save you rework, or rejected parts. The most critical element is to use the correct masking material for the critical dimensions, and exact locations as designated on the customer`s blueprint. The fit must be exacting and mirror the form of the finished product requirements.
Phosphate Coating: Zinc, Iron or Manganese Phosphate
Dry Film - Solid Film Lubricant
Gold Plating is used for many different electronic and electrical purposes, where the part is designed to operate on complex, high-reliability electronic devices. The majority being applied to three specific types of components: semiconductors, printed/etched circuits, contacts/connectors and high-end decorative items. Industries also use Gold plating for decorative applications. Gold plating can easily be applied to brass, aluminum, copper or steel.
Paint, Primers and Top Coats
Passivation, Shot Blast Finishing and Tumbling Finishes
Silk-screening is essentially a stencil printing method that begins with computer-generated artwork, which is comprised of a clear film. Silk-screening is performed through the use of stainless steel or cloth mesh screens, with either fine, or course mesh-counts and many ink types. The customers chosen design is applied directly to the product with paint, ink etc. Silkscreen is very versatile, and has a wide range of materials to which it can be applied. Some examples are: paper, all types of metal, glass, plastic and rubber. The size and shape of the product to be silkscreened is almost limitless.. Military, Telecommunications and Commercial Industries use silkscreening on boxes, panels and various other parts and products.
Zinc and Zincate Plating
Deeco Metals offers two types of Zinc plating: Alkaline Zinc exhibits good brightness, ductility and chromate receptivity, and has reliable and consistent coverage. Chloride Zinc deposits an outstanding brightness and plates difficult substrates such as castings. Zinc plating is used extensively on Automotive, Aerospace and Military products. It is available in Clear, Yellow or OD Green, and may be applied to steel, aluminum, copper or brass depending on the choice of zinc process.
Billet – A slug cut from rod to be heated and forged.
Blocker – Preformed die or impression, used when part cannot be made in a single operation.
Bottom Die – The stationary half-die.
Cavity – The impression in either the upper or lower die.
Die Shift – The impression of the top die not being in alignment with the impression of the bottom die, also, the amount of misalignment.
Draft – The taper on a vertical surface to facilitate the removal of the forging from the die or punch.- The taper on a vertical surface to facilitate the removal of the forging from the die or punch.
Fillet – A curved inside corner to increase the strength of an object at the corner and to improve appearance. Also important as it increases forging die life.
Flash – The excess metal that flows out between the upper and lower dies which is required to accomplish a desired forging shape.
Flash Extension – The amount of metal extending beyond the part at the flash line.
Flash Line – The line where the flash occurs.
Forging – The production of semi-finished forms from wrought metal blanks hot or cold in closed dies by a sudden, sharp impact. See “HAMMER FORGING” and “HOT PRESS FORGING”.
Gutter – A slight depression surrounding the cavity in the die to relieve pressure and control flash flow.
Hammer Forging – A forging process in which the piece is deformed by repeated blows.
Hardness – The resistance of a metal to plastic deformation by indentation. Common methods of measurement are Rockwell, Brinell, Scleroscope and Vickers.
Heat Check – Fine cracks in the forging dies caused by excessive heat or extended use without polishing. The pattern of these “heat checks” is reproduced on the forged part.
Heat Treatment – A combination of heating and cooling operations, applied to a metal or alloy in the solid state to produce desired properties.
Hot Press Forging – A method of forming parts by pressing a heated slug, cut from wrought material, in a closed-impression die.
Lubricate – Swabbing or spraying the dies with lubricant to assist in initial flow and to facilitate ejection of the forging.
Mismatch – Misalignment of forging at flash line caused by die or cavity positioning. (Mismatch should not exceed allowable tolerances).
Passivation or Vibratory Finishes – Various abrasive or polishing media is used in the process such as ceramic shapes, stainless balls, tree bark, metal chips, etc., to obtain many different finishes to metal parts.
Parting Line – The line where the dies come together and the flash is removed.
Shrinkage – The contraction that occurs when a forging cools.
Sink – To cut an impression in a die by EDM or CNC Milling.
Slug – The blank, cut from wrought material, from which a forging is made, see “BILLET”.
Tensile Strength – The value obtained by dividing the maximum load observed during tensile straining by the specimen cross-sectional area before straining. Also called “Ultimate Strength”.
Tolerance – The amount by which any characteristic such as dimensional, chemical, physical or mechanical properties, may vary from that specified.
Tumbling – Rolling in a revolving container to remove sharp edges and improve finish.
Web – The thin section of metal remaining at bottom of a cavity or depression in a forging. The web may be removed by piercing or machining.
Yield Strength – As commonly applied to copper and copper-base alloys, yield strength is the stress which will produce a .5 percent extension under load. It is known as “Yield Strength (.5 percent extension).
How to buy forgings?
1. Identify the product end use then decide the requirements in terms the strength, toughness, dimensional accuracy and overall integrity of a forging.The buyer should have a clear understanding of what their component specifically requires and ensure their needs can be met by individual forgers.
2. Identify the forging process required to make the product.This is a straightforward decision based on part size, configuration and quantity required.
3.Designing the product : One should clearly express how the desired forging will be used, the operating environment and critical mechanical properties. The forger needs to clearly understand the service stresses like load-bearing, power transmitting, impact, hydraulic pressure, operating temperatures, corrosive condition and the stress locations. This will help the engineer design and pass on suggestions to improve the overall product while reducing manufacturing costs.
4.Main design points:
a.Material Selection : Consider the tensile, hardness, impact and other mechanical properties are realistically based on the service requirements of the component being forged. select the best material for optimum performance, forgeability, heat treatability, machineability and cost.
B. Part Configuration : The forging engineer will look at its tooling and processing requirements and see where they can reduce draft angles or sharper radii without affecting part function. Often a simpler die can be used or the parting line can be adjusted to allow the use of a flat top die which will produce a more affordable part.
c.Dimensional Tolerances A wise buyer will see if the forger could help evaluate the trade-offs between reduced machining and increasing die and processing costs.
d.Machining : For open die forging, nearly all forgings will require some machining. Determining where and how much machining stock “envelope” should be specified and the complex decision is best made together with the forger.
e. Applying Guidelines – There is a system that was developed that act as dimensional tolerance guidelines that set limits on size, length, width and thickness, die match and straightness. Guidelines for impression die applications can be found in the Forging Industry Association’s Tolerances for Impression Die Forging, Hammer, Press and Upsetter.
f. Surface Finishing .
g.Inspection & Testing – The only tests that are needed will be ones that establish the mechanical properties and quality required for reliable performance. This will help keep costs low while also ensuring the part performs as needed because any additional tests will increase the cost. Non-destructive testing like ultrasonic and magnetic particle inspects have become increasingly important for critical service applications like generator or turbine rotor shafts. These tests are expensive and time-consuming so they should only be used when absolutely necessary. Statistical process/quality control techniques are being used in many forge shops and these capabilities could reduce the need for costly testing on individual
Some points to consider when choosing a forger.
-Does the forger have experience in applications similar to the one being considered?
-Is design assistance offered?
-Does the forger have the equipment required to produce your part?
-Is the forger able to provide related services like heat treating, machining and testing?
-Is the forger accustomed to producing the volume required?
-Does the company specialize in long runs, short runs or quick delivery?
-Is the forger capable of producing nonstandard alloys, specs & sizes?
Answering these questions is key to finding the qualified forger to meet your needs.
QUALITY CERTIFICATIONS / ENVIRONMENT / ENERGY certifications required for supplying forgings.
NADCAP Heat Treating
NADCAP Non Destructive Testing