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Oscar Antonio Ruano - One of the best experts on this subject based on the ideXlab platform.

  • Accumulative roll bonding of a Mg-based Az61 Alloy
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005
    Co-Authors: J A Del Valle, Maria Teresa Pérez-prado, Oscar Antonio Ruano
    Abstract:

    Abstract This work aims to investigate whether accumulative roll bonding (ARB) is an effective grain refinement technique for the Mg–Al Alloy Az61. Thus, a number of ARB routes at 300 °C and 400 °C, using thickness reductions per pass of 25%, 50%, 66%, and 80%, were performed. It was found that both the ultimate grain size achieved, as well as the degree of bonding, depend on the rolling temperature and on the thickness reduction per pass. Higher temperatures and higher reductions promote a larger degree of bonding. Increasing strain also favors the formation of a more homogeneous microstructure. The smallest grain sizes were obtained at the lowest rolling temperature.

  • effect of sheet thickness on the microstructural evolution of an mg Az61 Alloy during large strain hot rolling
    Scripta Materialia, 2004
    Co-Authors: M T Perezprado, J A Del Valle, Oscar Antonio Ruano
    Abstract:

    Abstract Using texture analysis and optical microscopy it has been found that, due to the large anisotropy of the hcp lattice, the deformation mechanism predominant during large strain hot rolling of an Az61 Mg Alloy changes from dislocation slip and rotational recrystallization (RRX) to twinning as the sheet thickness is reduced.

  • texture evolution during large strain hot rolling of the mg Az61 Alloy
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2003
    Co-Authors: J A Del Valle, M T Perezprado, Oscar Antonio Ruano
    Abstract:

    Abstract Grain refinement in a Mg-based Az61 Alloy of initially coarse, recrystallized microstructure was successfully achieved by thermomechanical processing (TMP) consisting of two to three hot-rolling steps with large reductions per pass. Reductions as large as 85% (equivalent to a true strain of ≈1) were achieved without surface cracking. The underlying microscopic mechanisms operative during the TMP that allowed this hcp material to accommodate such large strains per pass were investigated by macro- and microtexture analysis. A significant decrease in the intensity of the initial basal texture was observed after the first pass. This was attributed to rotational dynamic recrystallization, a mechanism by which new recrystallized grains develop, with orientations favourable for basal slip. Upon subsequent passes, basal slip becomes the main deformation mechanism. Simultaneously, grain refinement takes place by continuous dynamic recrystallization. The fine-grained microstructure thus developed showed improved superplastic behaviour in comparison with that of similar Alloys processed by more elaborate methods.

  • texture evolution during grain growth in annealed mg Az61 Alloy
    Scripta Materialia, 2003
    Co-Authors: M T Perezprado, Oscar Antonio Ruano
    Abstract:

    Abstract The development of new orientations in an extruded Mg based sheet Alloy is analysed upon annealing under different conditions. Normal grain growth takes place upon moderate annealing leading to a strong basal texture. Abnormal growth of prismatic { 1 1 2 0 } grains occurs following severe annealing treatments.

Jonghun Yoon - One of the best experts on this subject based on the ideXlab platform.

  • evolution of the microstructure and mechanical properties of Az61 Alloy processed by half channel angular extrusion hcae a novel severe plastic deformation process
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2013
    Co-Authors: Jonghun Yoon
    Abstract:

    Abstract A new concept of severe plastic deformation (SPD) process is introduced. The proposed process, named half channel angular extrusion (HCAE), which is the integration of equal channel angular extrusion (ECAE) and the conventional forward extrusion process in order to enhance the formability and mechanical properties of Mg Alloys. This paper focuses on the performance of HCAE process with extruded Az61 Alloy at elevated temperature in grain refinement and the improvement of mechanical properties, and this performance was evaluated through an OIM experiment using EBSD. The results show that the proposed HCAE process not only improves the efficiency of the SPD process with only one pass but also increase the elongation and hardness dramatically.

  • evolution of the microstructure and mechanical properties of Az61 Alloy processed by half channel angular extrusion hcae a novel severe plastic deformation process
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2013
    Co-Authors: Kyungjin Kim, Jonghun Yoon
    Abstract:

    Abstract A new concept of severe plastic deformation (SPD) process is introduced. The proposed process, named half channel angular extrusion (HCAE), which is the integration of equal channel angular extrusion (ECAE) and the conventional forward extrusion process in order to enhance the formability and mechanical properties of Mg Alloys. This paper focuses on the performance of HCAE process with extruded Az61 Alloy at elevated temperature in grain refinement and the improvement of mechanical properties, and this performance was evaluated through an OIM experiment using EBSD. The results show that the proposed HCAE process not only improves the efficiency of the SPD process with only one pass but also increase the elongation and hardness dramatically.

J A Del Valle - One of the best experts on this subject based on the ideXlab platform.

  • Accumulative roll bonding of a Mg-based Az61 Alloy
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2005
    Co-Authors: J A Del Valle, Maria Teresa Pérez-prado, Oscar Antonio Ruano
    Abstract:

    Abstract This work aims to investigate whether accumulative roll bonding (ARB) is an effective grain refinement technique for the Mg–Al Alloy Az61. Thus, a number of ARB routes at 300 °C and 400 °C, using thickness reductions per pass of 25%, 50%, 66%, and 80%, were performed. It was found that both the ultimate grain size achieved, as well as the degree of bonding, depend on the rolling temperature and on the thickness reduction per pass. Higher temperatures and higher reductions promote a larger degree of bonding. Increasing strain also favors the formation of a more homogeneous microstructure. The smallest grain sizes were obtained at the lowest rolling temperature.

  • effect of sheet thickness on the microstructural evolution of an mg Az61 Alloy during large strain hot rolling
    Scripta Materialia, 2004
    Co-Authors: M T Perezprado, J A Del Valle, Oscar Antonio Ruano
    Abstract:

    Abstract Using texture analysis and optical microscopy it has been found that, due to the large anisotropy of the hcp lattice, the deformation mechanism predominant during large strain hot rolling of an Az61 Mg Alloy changes from dislocation slip and rotational recrystallization (RRX) to twinning as the sheet thickness is reduced.

  • texture evolution during large strain hot rolling of the mg Az61 Alloy
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2003
    Co-Authors: J A Del Valle, M T Perezprado, Oscar Antonio Ruano
    Abstract:

    Abstract Grain refinement in a Mg-based Az61 Alloy of initially coarse, recrystallized microstructure was successfully achieved by thermomechanical processing (TMP) consisting of two to three hot-rolling steps with large reductions per pass. Reductions as large as 85% (equivalent to a true strain of ≈1) were achieved without surface cracking. The underlying microscopic mechanisms operative during the TMP that allowed this hcp material to accommodate such large strains per pass were investigated by macro- and microtexture analysis. A significant decrease in the intensity of the initial basal texture was observed after the first pass. This was attributed to rotational dynamic recrystallization, a mechanism by which new recrystallized grains develop, with orientations favourable for basal slip. Upon subsequent passes, basal slip becomes the main deformation mechanism. Simultaneously, grain refinement takes place by continuous dynamic recrystallization. The fine-grained microstructure thus developed showed improved superplastic behaviour in comparison with that of similar Alloys processed by more elaborate methods.

Enhou Han - One of the best experts on this subject based on the ideXlab platform.

Rongchang Zeng - One of the best experts on this subject based on the ideXlab platform.