Metal forming - Mechanical and thermal aspects

Metallic materials represent one of the three major classes of materials used by the manufacturing industry, alongside construction materials (concrete, mineral aggregates...) and natural polymers (cellulose extracted from wood to make paper, furniture or construction wood) and petroleum-based polymers (polyethylene...). They are also important components of composite materials: steel wires for reinforcing concrete or tires, binders for cemented carbides, such as tungsten carbides bound by a cobalt matrix and used as tools in machining, cold forging, wire drawing or as bearing components (balls...). They also have the advantage of being easy to recycle and reuse at low cost, with no loss of performance. Most everyday metal objects have undergone several shaping operations, in the solid and/or sheet state. The shaping of metals and metal alloys is therefore of considerable economic importance, generally accounting for a few percent of a developed country's gross national product.

Traditionally, the shaping of a metal part is followed by a heat treatment to give the part the microstructure and mechanical properties required for its use, or even a surface treatment to control its surface properties: roughness, mechanical, chemical and tribological properties. Forming techniques have evolved considerably since the 1960s: they are now aimed at directly supplying parts with the geometry, roughness, microstructure and mechanical properties required to meet a given specification, while saving energy and materials as much as possible, particularly rare and expensive alloying elements.

All in all, the shaping of metallic materials is a very important industrial sector, highly technical and constantly evolving, with a large number of problems, the resolution of which requires massive recourse to high-performance resources, such as test development and computer techniques. IT is used for three main reasons:

• process control and operation,

• setting up, managing and using databases on materials, processes, etc,

• scientific computing to numerically simulate an operation or chain of operations (shaping, heat treatment) in order to design operations (establish feasibility, estimate the cost of parts), solve set-up problems (eliminate part defects), optimize operations to improve productivity (reduce implementation energy and/or the quantity of material used, improve tool life).

It's hardly surprising, then, that shaping is one of the main outlets for the Productics market, an activity focused on the application of IT to manufacturing processes, and positioned ahead of ground transportation equipment, electrical and electronic construction, and polymer...