Entwicklung umformtechnischer Verfahren zum Nachverdichten von Sinterformteilen

Translated title of the contribution: Development of Forming Processes for the Redensification of P/M Parts

Florian Planitzer

Research output: ThesisDoctoral Thesis

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Abstract

Subject of this thesis is the development of processes that satisfy the growing demands on powder metallurgical (P/M) parts regarding strength and complex shapes. The approach pursued here is the improvement of the parts properties by increasing its density using forming operations. Hence, three strategies are pursued. To increase the strength of near-surface stressed parts, a surface densification by cold-extrusion is developed in a FE-study and accompanying laboratory experiments. To identify and extend the limits of the currently used sizing/repressing process, it is intensively examined in a FE-sensitivity analysis. Thus, basic interactions between preform and die are identified and used to formulate construction guidelines for preform design. Moreover, methods to exceed the process limits are proposed. With the approach of warm forming P/M parts, which is examined based on the repressing process in laboratory experiments, methods are shown to exceed the process limits of already used processes to manufacture parts with higher density, enhanced strength and more complex shapes. Regarding density and density distribution the examined processes fulfill the current requirements and those expected for the near future and so enhance the competitiveness of powder metallurgy. With the possibility to produce more complex-shaped surface- or completely densified parts, warm forming opens the door to new product groups and is therefore an interesting field of further research.
Translated title of the contributionDevelopment of Forming Processes for the Redensification of P/M Parts
Original languageGerman
QualificationDr.mont.
Supervisors/Advisors
  • Danninger, Herbert, Assessor B (external), External person
  • Buchmayr, Bruno, Assessor A (internal)
Publication statusPublished - 2011

Bibliographical note

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Keywords

  • powder metallurgy
  • metal forming
  • surface densification
  • densification
  • selectiv densification
  • extrusion
  • repressing
  • sizing
  • warm forming
  • PM
  • P/M

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