Temperature dependent mechanical properties of ultra-fine grained FeCo–2V

• Published in: Acta materialia Vol. 51; no. 14; pp. 4083 - 4093
• Main Authors: Duckham, A, Zhang, D.Z, Liang, D, Luzin, V, Cammarata, R.C, Leheny, R.L, Chien, C.L, Weihs, T.P
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 15.08.2003; Elsevier Science
• Subjects: Annealing; Applied sciences; Cross-disciplinary physics: materials science; rheology; Elasticity and anelasticity; Elasticity and anelasticity, stress-strain relations; Exact sciences and technology; High temperature tension testing; Materials science; Metals. Metallurgy; Physics; Severe plastic deformation; Treatment of materials and its effects on microstructure and properties; Ultra-fine grained microstructure; Yield phenomena; Annealing; Severe plastic deformation; Ultra-fine grained microstructure; High temperature tension testing; Yield phenomena; Temperature dependence; High strain; Vanadium alloys; Tensile tests; Ternary alloys; Mechanical properties; Iron alloys; Experimental study; Fine grain structure; True stress true strain curve; Cobalt alloys; Tensile properties
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/S1359-6454(03)00228-3

The tensile properties of ultra-fine grained ordered FeCo–2V have been investigated as a function of testing temperature. Samples with grain sizes of 100, 150 and 290 nm have been tested at temperatures ranging from 25 to 500 °C. Extremely high yield strengths (up to 2.1 GPa) were measured at room temperature with appreciable ductility of between 3 and 13%. These strengths were found to decline only gradually as the testing temperature was increased to 400 °C, while ductility was generally enhanced, up to 22%. The high strengths are attributed to grain boundary strengthening that is particularly effective due to ordering. Measured ductility was dependent on the relative values of yield strength, fracture strength and work hardening rate. Discontinuous yielding and appreciable Lüders strain (3–6%) were observed and were dependent on the initial structure and on the testing temperature.