Spin Forming Technology
In recent years, there has been a demand from the Original Engineering Manufacturers (OEMs) for components that are net or near net shape. Due to the shape complexity, many components are taxing current metal forming technologies beyond the capacity of producing them. Furthermore machining to shape is wasteful and should be minimised as a production operation. In order to meet this requirement, Spin Forming Technology (shear and flow forming) appears to be an attractive alternative to press formed or fully machined parts.
Shear forming is a process whereby cone shape parts are created from flat disc blanks. In practice, shear forming can also be adopted to produce concave, convex or a combination of two geometries. In addition, it can also be used in combination with flow forming process to produce parts with stepped intersections or where variation in wall thickness is required.
Flow forming, also known as tube spinning, is one of the techniques closely allied to shear forming. In this process, the metal is displaced axially along a mandrel, while the internal diameter remains constant. It is usually employed to produce cylindrical components. The starting blank can be in the form of a sleeve or cup. Blanks can be produced by spinning, deep drawing or forging plus machining to improve the dimensional accuracy. In many cases, flow forming is combined with splitting & shear forming processes to produce cylindrical components with flanges of stepped intersections.
Contact PersonChua Beng Wah(bwchua@SIMTech.a-star.edu.sg)
SolutionIn SIMTech, extensive studies were carried out to understand the deformation characteristics and spin formability of many materials (Aluminum, Titanium, Magnesium, as-cast performs, high strength etc.) under different forming conditions, adopting both experimental and Finite Element modelling & simulation. In addition, metallurgical studies were carried out in order to study the effect of texture on spin formability.
Because of its unique deformation characteristics (localised deformation), spin forming can be used to form ‘hard to form’ or low ductility materials which traditionally is very difficult to produce by conventional stamping or forging processes. In general, metals that posses homogenous structure can be spin formed which include: Aluminum alloys, Copper, Carbon Steel, Low Alloy Steel, Stainless Steel, Bearing Steel, Maraging Steel, Nickel Based Alloys, Titanium Alloys, Magnesium Alloys.
For axisymmetrical components such as:
- Cylindrical straight, conical, convex and concave profile.
- Single/double V grooved or poly V pulley.
- Internal intricate features such as splines & undercut profile.
- Peripheral intricate features such as flange, boss & wheel rim profiles.