Additive Manufacturing and Precipitation Hardening of Low-Alloyed Copper Alloys Containing Chromium and Hafnium

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Julia Dölling - , Deutsches Zentrum für Luft- und Raumfahrt (DLR) e.V. (Autor:in)
  • Samira Gruber - , Fraunhofer-Institut für Werkstoff- und Strahltechnik (Autor:in)
  • Felix Kovermann - , cunova GmbH (Autor:in)
  • Lukas Stepien - , Fraunhofer-Institut für Werkstoff- und Strahltechnik (Autor:in)
  • Elmar Beeh - , Deutsches Zentrum für Luft- und Raumfahrt (DLR) e.V. (Autor:in)
  • Elena Lopez - , Fraunhofer-Institut für Werkstoff- und Strahltechnik (Autor:in)
  • Christoph Leyens - , Fraunhofer-Institut für Werkstoff- und Strahltechnik (Autor:in)
  • Hans Günther Wobker - , cunova GmbH (Autor:in)
  • Andreas Zilly - , Universität Stuttgart (Autor:in)

Abstract

Copper alloys with chromium and hafnium offer the possibility of precipitation hardening and combine enhanced strength with high electrical and thermal conductivities. The production process, which starts with raw materials, involves powder production by gas atomization and leads to additive manufacturing by laser powder bed fusion with different parameter sets. The aim is to utilize precipitation reactions afterwards in CuHf0.7Cr0.35 during temperature exposure for further property optimization. This research focuses on the low-alloyed copper alloy with hafnium and chromium, compares this with conventionally manufactured specimens, and relates the alloy to additively manufactured specimens of other benchmark alloys such as CuCr1Zr. Measurements of hardness and electrical conductivity are accompanied by metallographic investigations to understand the behavior of CuHf0.7Cr0.35 manufactured by generative methods. In the as-built condition, melting traces remain visible in the microstructure, and hardness values of 101 HV and an electrical conductivity of 17.5 MS/m are reached. Solution annealing completely recrystallizes the microstructure, and the following quenching holds further alloying elements in supersaturated solid solution, resulting in 73 HV and 16.5 MS/m. Subsequent target-oriented precipitation reactions enable peak values of about 190 HV and 42 MS/m. Future research will assess mechanical and physical properties at elevated temperatures and evaluate possible applications.

Details

OriginalspracheEnglisch
Aufsatznummer1304
FachzeitschriftMetals
Jahrgang14
Ausgabenummer11
PublikationsstatusVeröffentlicht - Nov. 2024
Peer-Review-StatusJa
Extern publiziertJa

Schlagworte

Schlagwörter

  • conductivity improvement, copper–chromium CuCr, copper–hafnium CuHf, laser powder bed fusion, precipitation hardening, short wavelength laser system