The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform

Chuan Song Wu - One of the best experts on this subject based on the ideXlab platform.

  • Material flow in ultrasonic vibration enhanced friction stir welding
    Journal of Materials Processing Technology, 2015
    Co-Authors: Chuan Song Wu
    Abstract:

    Abstract An ultrasonic vibration enhanced friction stir welding (UVeFSW) system was developed, in which the ultrasonic energy was transmitted directly into the localized area of the workpiece near and ahead of the rotating tool by a specially-designed sonotrode. The interaction mechanism of the ultrasonic vibration with the Deformed Material around the FSW tool was investigated experimentally by integrating three configurations of marker Material and metallographic analysis. The observation and comparison of the marker Material distribution on different cross-sections of butt-weld specimens revealed that there were two main Material flow patterns in stir zone of 2024-T4 aluminium alloy butt welds in UVeFSW, i.e., the continuous flow (upper one third of weld) and the non-continuous flow (lower two thirds of weld). The ultrasonic energy enlarged the volume of the Deformed Material around the pin, enhanced the stability of the continuous Material flow and the Material strain of the non-continuous flow obviously, and weakened the degree of vertical Material transfer. The results provided a reasonable explanation for the improvement of weld joint quality in UVeFSW.

  • Characterization of plastic deformation and Material flow in ultrasonic vibration enhanced friction stir welding
    Scripta Materialia, 2015
    Co-Authors: Xiaochao Liu, Chuan Song Wu, G K Padhy
    Abstract:

    Material flow and plastic deformation in ultrasonic vibration enhanced friction stir welding are visualized by employing a special marker Material and welding procedure. Based on the results, three methods are developed to evaluate the volume of Deformed Material, the Material flow velocity and the strain/strain rate, and the effect of ultrasonic vibration on the plastic deformation and Material flow around the tool is characterized.

G K Padhy - One of the best experts on this subject based on the ideXlab platform.

Xiaochao Liu - One of the best experts on this subject based on the ideXlab platform.

Satyam Suwas - One of the best experts on this subject based on the ideXlab platform.

  • Shear band widening mechanism in Ti–6Al–4V under high strain rate deformation
    Journal of Materials Research, 2020
    Co-Authors: Anuj Bisht, Subhash Kumar, Ka Ho Pang, Rongxin Zhou, Anish Roy, Vadim V. Silberschmidt, Satyam Suwas
    Abstract:

    In this study, mechanical properties and microstructural investigation of Ti64 at high strain rate are studied using a split-Hopkinson pressure bar method under compression for temperatures up to 800 °C. Flow softening in the mechanical response of Material to such loading conditions hints at instability in compression, which increases with an increase in temperature. Microstructural characterization of the Deformed Material is characterized using the electron-backscattered diffraction technique. It reveals the presence of instabilities in Ti64 in the form of a fine network of shear bands. The shear band width grows with an increase in temperature along with the area fraction of shear band in the Material, displaying its improved capacity to contain microstructural instabilities at higher temperature. After a detailed microstructural investigation, a mechanism for shear band widening is proposed. Based on this mechanism, a path generating nuclei within shear bands is discussed.

  • Effect of stacking fault energy on the evolution of microstructure and texture during blast assisted deformation of FCC Materials
    Journal of Materials Processing Technology, 2019
    Co-Authors: Anuj Bisht, Lailesh Kumar, Janardhanraj Subburaj, Gopalan Jagadeesh, Satyam Suwas
    Abstract:

    Abstract Effect of stacking fault energy (SFE) on microstructural and crystallographic aspect of high-velocity deformation of FCC metals (Ni, Cu, and austenitic stainless steel) via blast assisted deformation have been investigated in this work. Microstructural changes have been probed via XRD line profile analysis and electron back-scattered diffraction methods along with TEM analysis for selected samples. The texture of all Deformed Material tends towards a developed α-fiber, which is observed to be strain-dependent. The relative fraction of Brass to Goss texture components increases with a decrease in SFE. The annealing twin boundaries, present in the initial Material, transform in segments or full to high angle random boundary in all the Material due to the dislocation pile-up. However, the microstructure of the Deformed Material depends heavily on the SFE, with nickel showing dislocation cells, and, austenitic stainless steel (ASS) has a mix of features of homogeneous dislocation, deformation bands, and deformation twins. Relatively thick deformation twins form in grains having orientations other than {110} plane normal to the blast direction. The overall microstructure of ASS gives an impression of a superimposed microstructure. Such structure is expected to be a result of shock passage through the Material followed by macroscopic straining. No such superimposed microstructure has been observed in nickel which is attributed to recovery behavior prevalent in high SFE Materials.

Daniel Fabijanic - One of the best experts on this subject based on the ideXlab platform.

  • tension compression asymmetry in additive manufactured face centered cubic high entropy alloy
    Scripta Materialia, 2017
    Co-Authors: Jithin Joseph, Nicole Stanford, Peter Hodgson, Daniel Fabijanic
    Abstract:

    Abstract The high entropy alloy, Al0.3CoCrFeNi, has been fabricated by direct laser fabrication and its deformation behaviour studied. This alloy exhibited significant tension/compression asymmetry in its work hardening rate and ductility. The exceptionally high work hardening in compression has been attributed to profuse mechanical twinning which has been exacerbated by a strong texture in the as-cast Material. The tensile Deformed Material did not exhibit any mechanical twinning, Deformed exclusively by slip, and therefore showed minimal work hardening and poor ductility. The critical resolved shear stress for twinning of the alloy was found to be approximately 240 MPa.

  • Tension/compression asymmetry in additive manufactured face centered cubic high entropy alloy
    Scripta Materialia, 2017
    Co-Authors: Jithin Joseph, Nicole Stanford, Peter Hodgson, Daniel Fabijanic
    Abstract:

    Abstract The high entropy alloy, Al0.3CoCrFeNi, has been fabricated by direct laser fabrication and its deformation behaviour studied. This alloy exhibited significant tension/compression asymmetry in its work hardening rate and ductility. The exceptionally high work hardening in compression has been attributed to profuse mechanical twinning which has been exacerbated by a strong texture in the as-cast Material. The tensile Deformed Material did not exhibit any mechanical twinning, Deformed exclusively by slip, and therefore showed minimal work hardening and poor ductility. The critical resolved shear stress for twinning of the alloy was found to be approximately 240 MPa.