S. Mueller, S. Gall, R. Nitschke, A. Goraieb
FORMING GmbH,
Germany
Keywords: Beryllides, extrusion, powder
Summary:
The alloying of Beryllium and Titanium can only be done through the powder metallurgical route thus, the aim of the extrusion of the Beryllium-Titanium powder is to densify and form the powder during the extrusion to receive an almost 100% dense bulk material. To extrude the powder on a regular industrial scale extrusion press the powder must ne kept in a container during handling, heating and extrusion. Furthermore, the extrusion have to be performed at high temperatures in order to be able to deform the Beryllides and to achieve the high density. But the temperature during the extrusion must not exceed 750 °C since brittle phases form above this temperature. The solution to the described challenges that was developed at the Extrusion Research and Development Center in Berlin is the coextrusion of the Beryllides in an double containment at 700 °C. The double containment consists of an inner container made of Niobium which is holding the Beryllide powder. The outer container has fulfill various requirements. It has to work as a lubricant during the extrusion, be able to control the temperature inside the inner container and has to have an equal deformation behavior as the Beryllide powder at the chosen extrusion temperature of 700 °C.