Micro-addition of Fe in highly alloyed Cu-Ti alloys to improve both formability and strength

Materials & Design

Cyril Cayron¹  B. Rouxel²  Julien Bornand²  Roland E. Logé³  Paul Sanders⁴ 

[1] Corresponding author.;Laboratory of Thermomechanical Metallurgy (LMTM), PX Group Chair, Ecole Polytechnique Fédérale de Lausanne (EPFL), Rue de la Maladière 71b, Neuchâtel, 2002, Switzerland;Michigan Technological University, Materials Science and Engineering, Houghton, MI 49931, USA;Swiss-Tube LN Industries, Rue du Moulin 1, 1424 Champagne, Switzerland;

关键词: Cu-Ti alloys;    High-strength copper alloy;    Spinodal decomposition;    Precipitation strengthening;    Phase transformation;    alternative alloys to Cu-Be;   

DOI  :  

来源: DOAJ

【 摘 要 】

Cu-Be alloys provide excellent electrical and mechanical properties, but present serious health hazards during manufacturing. Among alternative alloys, the Cu-Ti system has the highest yield strength; however, Ti cannot be easily solutionized at concentrations above 4 wt%, resulting in a relatively low formability. In this study, Cu-xTi-yFe (x = 3, 5, 6 wt% and y = 0, 0.3 wt%) alloys were studied after both solution-annealing and age-hardening through mechanical testing and microstructure analysis. Micro-additions of Fe kept high concentration of Ti in solid solution (up to 6 wt%) after water quenching and suppressed the classical “wave-like” early-stage precipitation. Instead, a new dispersion of nano precipitates was observed. This behavior results in doubling the ductility in the solution annealed state (up to 48% elongation), together with maintaining a very high strength after ageing (up to 975 MPa) from precipitation of metastable nano α-Cu4Ti. This study shows that Fe micro-additions, when combined with a higher amounts of Ti (6 wt%), enables the production of Cu-based alloys combining high formability and strength, providing an excellent alternative to Cu-Be in mechanical applications.

【 授权许可】

Unknown