Microstructure Mechanisms Governing the Creep Life of Ultrafine-Grained Cu-0.2 wt%Zr Alloy

• Authors: P. Kral , M. Svoboda , J. Dvorak , M. Kvapilova , V. Sklenicka
• Languages of publication: EN

Abstracts

EN

Equal-channel angular pressing was conducted at room temperature and extrusion was performed up to 12 passes using route where the billets were rotated by 90° in the same sense between consecutive passes. Tensile creep tests were performed at 473, 573 and 673 K at different constant applied stresses. It was observed that the original coarse grain size of unprocessed alloy was reduced to 0.3 μm after 8 equal-channel angular pressing passes and the grain growth during creep was restricted by precipitates with the mean diameter ≈ 4.0 nm. No significant effect on creep resistance was found after one equal-channel angular pressing pass at 473 and 573 K. However, the longest time to fracture was exhibited by alloy after 2 equal-channel angular pressing passes at 573 and 673 K but with further increasing number of equal-channel angular pressing passes a decrease in the time to fracture was observed. Nevertheless, the beneficial effect of equal-channel angular pressing on creep resistance was still documented after 8 passes for temperatures of 473 and 573 K. By contrast, creep tests performed at 673 K showed that the time to fracture of ultrafine-grained material is shorter as compared with that for as-received state. The 3D laser measurement of surface showed that the creep fracture process is accelerated by formation of vertical surface step relief and cavitation at the intersection of the shear bands during creep.

Keywords

EN

81.05.-t; 61.66.Dk; 62.20.Hg; 68.37.Lp

Discipline

• 68.37.Lp: Transmission electron microscopy (TEM)
• 62.20.Hg: Creep
• 81.05.-t: Specific materials: fabrication, treatment, testing, and analysis(for superconducting materials, see 74.70.-b, and 74.72.-h; for magnetic materials, see 75.50.-y; for optical materials, see 42.70.-a; for dielectric materials, see 77.84.-s; for disperse systems and complex fluids, see 82.70.-y; see also 82.75.-z Molecular sieves, zeolites, clathrates, and other complex solids; for materials properties, see sections 60 and 70)
• 61.66.Dk: Alloys

• Journal: Acta Physica Polonica A
• Year: 2012
• Volume: 122
• Issue: 3
• Pages: 457-460

Dates

published

2012-09

Contributors

author

P. Kral

• Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, 616 62 Brno, Czech Republic

author

M. Svoboda

• Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, 616 62 Brno, Czech Republic

author

J. Dvorak

• Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, 616 62 Brno, Czech Republic

author

M. Kvapilova

• Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, 616 62 Brno, Czech Republic

author

V. Sklenicka

• Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, 616 62 Brno, Czech Republic

References

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Identifiers

DOI

10.12693/APhysPolA.122.457