13-2 Forgings Forging consists of plastically deforming, either by a squeezing pressure or sharp blows, a cast or sintered ingot, a wrought bar or billet, or a powder-metal shape, to produce a desired shape with good mechanical properties. Practically all ductile materials can be forged

Closed-Die Forging Made by hammering or pressing metal until it conforms closely to the shape of the enclosing dies “closed-die forging” is the term applied to all forging operations involving 3-D control Impression die – Workpiece placed on bottom half die – Top-half die closed and workpiece undergoes elastic compression until its enlarged sides touch the side walls of the die impression – Excess material-flash 3 main classes – Single-impression – Double-impression – interlocking

MANUFACTURING MATERIAL FORGING DIES

General design rules Corner & fillet radii- should be sufficient to facilitate the flow of metal – Cold shuts: a lap where 2 surfaces have folded against eachother forming a weak spot that may open into a crack – Cold shuts occur where there are sharp fillets or deep sections Draft angle- the slope given to the side walls of the die in order to facilitate removal of the forging (usually 7°exterior contours and 10° interior contours) Parting Line- line of meeting of the dies

Drafting Practices particular to forging Draft angles and parting lines Corner and fillet radii Forging tolerances Heat treatment Locations of trademark, part number, and vendor specs

Dimensioning Depth of the die impression Only one dimension from the parting line. This surface is then used to establish other dimensions (figure 13-30) Allowances for machining Composite drawings- generally the forged part is shown on one drawing with the forging outline shown in phantom lines

MANUFACTURING MATERIAL FORGING DRAWING

MANUFACTURING MATERIAL MACHINING DRAWING