Hot Isothermal Forging for "Near Net Shape” Technologies

A final consolidation step in powder metallurgy is used to achieve full density and full strength. The more common consolidation methods are:
• Sintering;
• Hot isostatic pressing;
• Forging;
• Hot extrusion.

Parts from metals and alloys, such as titanium and various superalloys, that are hard to shape and are used in jet-engine parts subjected to high stresses, as well as metals such as molybdenum which retain high strength at high temperatures are usually finished by hot isothermal forging (HIF). Hot isothermal forging (HIF) has developed in recent years into an important – and for many applications indispensable – process for producing high-quality parts in “near net shape”.

Isothermal Forging System Design
A prerequisite for such metallurgical “constancy” of the workpiece is the superplastic deformation, which can be achieved with extremly low deformation rates in a narrow temperature band. If the forging is done under superplastic conditions, maintaining certain parameters, only small stresses occur in the workpiece and the grain size remains nearly unchanged. Another advantage of this deformation method is the “near net shape” potential and the related savings in materials plus a greatly reduced need for subsequent machining. HIF systems from ALD feature:
• The multizone billet heating furnace;
• The multizone die-heating system;
• The microprocessor-controlled system for temperature control.