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Clegg William - One of the best experts on this subject based on the ideXlab platform.

  • Deformation of lamellar TiAl Alloys by longitudinal twinning
    Scripta Materialia, 2016
    Co-Authors: Edwards Thomas, Di Gioacchino Fabio, Muñoz-moreno R, Clegg William
    Abstract:

    © 2016 Elsevier Ltd. The occurrence of longitudinal twinning in the Engineering Alloy Ti-45Al-2Nb-2Mn (at.%)-0.8 vol.% TiB2 has been studied by measuring the changes in crystallographic orientation within individual lamellae during microcompression. Twinning in this Alloy appeared to be a nucleation-limited process with the twins growing from lamellar boundaries at resolved shear stresses as low as 100 MPa, consistent with observations elsewhere. However, instead of forming twins ∼ 10-200 nm in thickness, as in polysynthetically twinned crystals, the longitudinal twins in this Alloy were initiated at a lamellar boundary and then spread through the whole lamella

Edwards Thomas - One of the best experts on this subject based on the ideXlab platform.

  • Deformation of lamellar TiAl Alloys by longitudinal twinning
    Scripta Materialia, 2016
    Co-Authors: Edwards Thomas, Di Gioacchino Fabio, Muñoz-moreno R, Clegg William
    Abstract:

    © 2016 Elsevier Ltd. The occurrence of longitudinal twinning in the Engineering Alloy Ti-45Al-2Nb-2Mn (at.%)-0.8 vol.% TiB2 has been studied by measuring the changes in crystallographic orientation within individual lamellae during microcompression. Twinning in this Alloy appeared to be a nucleation-limited process with the twins growing from lamellar boundaries at resolved shear stresses as low as 100 MPa, consistent with observations elsewhere. However, instead of forming twins ∼ 10-200 nm in thickness, as in polysynthetically twinned crystals, the longitudinal twins in this Alloy were initiated at a lamellar boundary and then spread through the whole lamella

Di Gioacchino Fabio - One of the best experts on this subject based on the ideXlab platform.

  • Deformation of lamellar TiAl Alloys by longitudinal twinning
    Elsevier B.V., 2016
    Co-Authors: Edwards, Thomas Edward James, Di Gioacchino Fabio, Muñoz-moreno Rocío, Clegg, William John
    Abstract:

    AbstractThe occurrence of longitudinal twinning in the Engineering Alloy Ti-45Al-2Nb-2Mn (at.%)-0.8vol.% TiB2 has been studied by measuring the changes in crystallographic orientation within individual lamellae during microcompression. Twinning in this Alloy appeared to be a nucleation-limited process with the twins growing from lamellar boundaries at resolved shear stresses as low as 100MPa, consistent with observations elsewhere. However, instead of forming twins ~10–200nm in thickness, as in polysynthetically twinned crystals, the longitudinal twins in this Alloy were initiated at a lamellar boundary and then spread through the whole lamella

  • Deformation of lamellar TiAl Alloys by longitudinal twinning
    Scripta Materialia, 2016
    Co-Authors: Edwards Thomas, Di Gioacchino Fabio, Muñoz-moreno R, Clegg William
    Abstract:

    © 2016 Elsevier Ltd. The occurrence of longitudinal twinning in the Engineering Alloy Ti-45Al-2Nb-2Mn (at.%)-0.8 vol.% TiB2 has been studied by measuring the changes in crystallographic orientation within individual lamellae during microcompression. Twinning in this Alloy appeared to be a nucleation-limited process with the twins growing from lamellar boundaries at resolved shear stresses as low as 100 MPa, consistent with observations elsewhere. However, instead of forming twins ∼ 10-200 nm in thickness, as in polysynthetically twinned crystals, the longitudinal twins in this Alloy were initiated at a lamellar boundary and then spread through the whole lamella

Mahyar Asadi - One of the best experts on this subject based on the ideXlab platform.

  • constructing a validated deformation mechanism map using low temperature creep strain accommodation processes for waspaloy a nickel based superAlloy
    ASME 2013 Pressure Vessels and Piping Conference, 2013
    Co-Authors: Mahyar Asadi, Dominic Guillot, Arnaud Weck, A K Koul, A Chamanfar, M Jahazi
    Abstract:

    A creep Deformation Mechanism Map (DMM) of an Engineering Alloy can be an effective tool for developing physics based prognostics systems. Many classical diffusion based rate equations have been developed for time dependent plastic flow where dislocation glide, dislocation glide-plus-climb and vacancy diffusion driven grain boundary migration (diffusion creep) are rate controlling. Long term creep testing and analysis of complex Engineering Alloys has shown that power law breakdown phenomenon is related to the dominance of Grain Boundary Sliding (GBS) as opposed to diffusion creep. Rate equations are now available for GBS in complex Alloys and, in this paper, a DMM is constructed for Waspaloy (a Nickel-Based SuperAlloy) and validated by comparison with a collection of experimental data obtained from the literature. The GBS accommodated by wedge type cracking is considered dominant at low homologous temperatures (0.3 to 0.5Tm - temperature in Kelvin) whereas GBS accommodated by power-law or cavitations creep dominates above 0.55Tm.Copyright © 2013 by ASME

  • constructing a validated deformation mechanisms map using low temperature creep strain accommodation processes for nickel base Alloy 718
    ASME 2012 Pressure Vessels and Piping Conference, 2012
    Co-Authors: Mahyar Asadi, Dominic Guillot, Arnaud Weck, A K Koul, Subray R Hegde, Trevor Sawatzky, H Saari
    Abstract:

    A creep Deformation Mechanism Map (DMM) of an Engineering Alloy can be an effective tool for developing physics-based prognostics systems. Many classical diffusion based rate equations have been developed for time dependent plastic flow where dislocation glide, dislocation glide-plus-climb and vacancy diffusion driven grain boundary migration (diffusion creep) are rate controlling. These creep rate equations have been proven experimentally for simple metals and Alloys and form the basis of constructing an Ashby’s DMM. Long term creep testing and analysis of complex Engineering Alloys has shown that power law breakdown phenomenon is related to the dominance of Grain Boundary Sliding (GBS) as opposed to diffusion creep. Rate equations are now available for GBS in complex Alloys and, in this paper, a DMM is constructed for a fine grained Alloy 718 and this is validated by comparison with a collection of experimental data obtained from the literature. The GBS accommodated by wedge type cracking is considered dominant at low homologous temperatures (0.3 to 0.5Tm i. e. melting temperature in Kelvin) whereas GBS accommodated by power-law or cavitation creep dominates above 0.55Tm.Copyright © 2012 by ASME

Muñoz-moreno R - One of the best experts on this subject based on the ideXlab platform.

  • Deformation of lamellar TiAl Alloys by longitudinal twinning
    Scripta Materialia, 2016
    Co-Authors: Edwards Thomas, Di Gioacchino Fabio, Muñoz-moreno R, Clegg William
    Abstract:

    © 2016 Elsevier Ltd. The occurrence of longitudinal twinning in the Engineering Alloy Ti-45Al-2Nb-2Mn (at.%)-0.8 vol.% TiB2 has been studied by measuring the changes in crystallographic orientation within individual lamellae during microcompression. Twinning in this Alloy appeared to be a nucleation-limited process with the twins growing from lamellar boundaries at resolved shear stresses as low as 100 MPa, consistent with observations elsewhere. However, instead of forming twins ∼ 10-200 nm in thickness, as in polysynthetically twinned crystals, the longitudinal twins in this Alloy were initiated at a lamellar boundary and then spread through the whole lamella