Stabilization of L12 structured Cr3Cu precipitates in a Cu-4.06Cr-1.25Nb alloy with high high-temperature strength. Issue 4 (3rd April 2022)

• Record Type: Journal Article
• Authors: Yang, Y. H.; Lei, Q.; Zhang, P.; Wang, W. Y.; Zhang, X. K.; Li, Y. P.; Zhou, K. C.; Li, Z.
• Is Part Of: Materials research letters. Volume 10:Issue 4(2022)
• Page Start: 257
• Page End: 263
• Publication Date: 2022-04-03
• Subjects: Copper alloys -- precipitation -- coarsening -- first-principles calculation; Materials science -- Research -- Periodicals; Biomedical materials -- Research -- Periodicals; Composite materials -- Research -- Periodicals; Biomedical materials -- Research; Composite materials -- Research; Materials science -- Research; Periodicals; 620.1105
• DOI: 10.1080/21663831.2022.2035838
• Languages: English
• ISSNs: 2166-3831

Abstract

Abstract : Stable L12 structured Cr3 Cu precipitates were determined in a Cu-4.06Cr-1.25Nb alloy rather than b.c.c. structured Cr precipitates by transmission electron microscope (TEM) and three-dimension atom probe tomography (3DAP) at 450 o C. The precipitation sequence of the studied alloy aged at 400 o C was supersaturated solid solution → f.c.c. Cr phase → Cr3 Cu phase (L12 ). Nb atoms would segregate in the interface between the Cu and Cr phase, reduce the Cu/Cr interfacial energy, affect the precipitation, growth, phase transformation, and coarsening of the precipitate. These Cr3 Cu precipitates significantly improved the high-temperature strength of the Cu-Cr-Nb alloy (223 ± 5 MPa at 500 o C). GRAPHICAL ABSTRACT: UF0001 IMPACT STATEMENT: TEM images and calculations revealed that Nb can stabilize metastable Cr3 Cu precipitates (L12 ) by reducing the Cu/Cr interfacial energy, and provide a higher high-temperature strengthening effect than b.c.c. Cr.