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Gradation Extrusion - Integration of Severe Plastic Deformation into Impact Extrusion Process

Presentation held at 35th SENAFOR, 19th International Forging Conference, 18th National Sheet Forming Conference / 5th International Sheet Metal Forming Conference / 2nd BDDRG Congress, 5th RenoMat - International Conference on Materials and Processes for Renewable Energy, October 7th to 9th, 2015, Porto Alegre, Brazil
 
: Bergmann, Markus; Oliveira, Raoni B. de; Rautenstrauch, Anja; Selbmann, Rene; Landgrebe, Dirk; Coelho, Rodrigo S.

:
Fulltext urn:nbn:de:0011-n-3666258 (556 KByte PDF)
MD5 Fingerprint: 1f0f01d09492829543a5a343811ca1ad
Created on: 18.11.2015


2015, 6 pp.
Seminar of National Forging (SENAFOR) <35, 2015, Porto Alegre>
International Forging Conference <19, 2015, Porto Alegre>
National Sheet Forming Conference <18, 2015, Porto Alegre>
International Sheet Metal Forming Conference <5, 2015, Porto Alegre>
BDDRG Congress <2, 2015, Porto Alegre>
International Conference on Materials and Processes for Renewable Energy (RenoMat) <5, 2015, Porto Alegre>
English
Presentation, Electronic Publication
Fraunhofer IWU ()
gradation extrusion; ultrafine-grained material; severe plastic deformation; titanium; aluminum

Abstract
Conventional Severe Plastic Deformation (SPD) processes, such as equal channel angular pressing (ECAP) and high pressure torsion (HPT), have been used for mechanical improvement of commercially pure titanium. These techniques usually impose a relatively homogeneous deformation to the whole material volume. In this way, the mechanical properties generated due to the grain refinement from the process are uniformly distributed throughout the workpiece. A new technique, known as Gradation Extrusion, has been developed with the objective to produce a deformation gradient in the workpiece through a process that combines SPD forming and impact extrusion. This method allows to create a fine-grained structure near the surface and an increasing grain size in radial direction of the extruded bar. This microstructure distribution influences the material properties, providing to the material a high mechanical strength near the surface and a relatively good ductility due to the less refined core. These properties are interesting for several applications, such as dental implant or bolt manufacturing. A high level of mechanical strength is obtained, while a sufficient level of ductility is maintained which is needed to form the inner shape of the product. This work aims to evaluate the main advantages of the proposed method to possible industrial applications. Numerical simulations, experimental tests, microstructure analysis and microhardness tests were developed to assist the investigation.

: http://publica.fraunhofer.de/documents/N-366625.html