Browsing by Author "Pan, Z"

Now showing 1 - 6 of 6
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    Development of a DC-LSND welding process for GMAW on DH-36 steel
    (Australian Institute of Nuclear Science and Engineering (AINSE), 2013-11-02) Paradowska, AM; Law, M; Larkin, N; Holder, R; Li, H; Kuzmikova, L; Pan, Z; Norrish, J; Shen, C
    The reduction of weld induced distortion has become an important focus of research for the shipbuilding industry with the continuing trend of using thinner plates in the ship's hull and super structure. This paper investigates the use of an active cooling process known as Dynamically Controlled—Low Stress No Distortion (DC-LSND) Welding on medium thickness (5 to 6 mm) DH-36 steel. Thermal profiles are obtained. Hardness, distortion and residual stress measurements are also achieved. Results show that the application of a localized cryogenic cooling source trailing the welding arc can significantly reduce weld induced distortion and residual stress using the GMAW process. And welds done by DC-LSND process show a hardening and brittle tendency. The effect of forced cooling on the weld microstructure is also observed.
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    Development of a new powder-bed arc additive manufacturing approach for producing high entropy alloys
    (Materials Australian and The Australian Ceramic Society, 2022-06-01) Dong, BS; Wang, ZY; Pan, Z; Li, HJ
    High entropy alloys (HEAs) have gained significant attention over the past decade from both academic and industrial communities due to their unique design concept and promising properties. The manufacturing of this emerging material with desired properties remains challenging. A new powder-bed arc additive manufacturing (PAAM) has been developed at the University of Wollongong for producing HEAs. This approach, with a high level of flexibility for controlling the forming process and the characteristic rapid solidification, enables the tailoring of the microstructure through the process control and the effective reduction of the chemical segregation in these compositionally complexed alloys. Additionally, compared with the laser and electron beam based additive manufacturing, PAAM is advantageous for higher production rate hence it is promising in industrial applications for producing bulk components in shorter period. The production of a eutectic AlCoCrFeNi2.1 HEA using this new PAAM approach will be presented to demonstrate its capability. Then, the FeCr0.4V0.3Ti0.2Ni1.3 HEA with low neutron cross-section is successfully designed and fabricated in this system. The good tensile properties of this novel HEA make it become a potential candidate as a structural material in the future nuclear industry.
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    Effects of heat treatment on microstructure and mechanical properties of wire arc additively manufactured Hastelloy C276 alloy
    (Materials Australian and The Australian Ceramic Society, 2022-06-01) Qiu, Z; Wu, B; Zhu, H; Wang, Z; Wexler, D; Van Duin, S; Pan, Z; Li, H
    Hastelloy C276 is a Ni-Cr-Mo based superalloy which has a high potential for application in high temperature and extreme corrosive environment due to its high corrosion resistance and excellent mechanical properties. In this research, the wire arc additive manufacturing (WAAM) process was successfully used to fabricate the defect-free Hastelloy C276 component. The microstructure of the component was characterized using optical microscopy, scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction, the mechanical properties were evaluated via tensile and hardness tests. The as-deposited component exhibited anisotropy on both microstructure and mechanical properties. The influences of solid solution heat treatment and stress relief heat treatment on microstructure and mechanical properties were also investigated. It was found that both microstructure and mechanical properties were significantly modified after heat treatment. Preliminary creep tests indicted the texture has a strong influence on the creep performance of the component.
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    Neutron diffraction residual stress measurements of weldments for shipbuilding application
    (Australian Institute of Nuclear Science and Engineering (AINSE), 2012-11-15) Shen, C; Paradowska, AM; Larkin, N; Li, H; Pan, Z; Law, M
    Pulsed tandem gas metal arc welding (PT-GMAW) has been identified as a welding process potentially capable of increasing productivity and minimising distortion in ship-building. For this study, the PT-GMAW process was used in pulse-pulse mode to butt-weld DH36 steel in order to determine its suitability as a replacement for standard gas-metal-arc welding and submerged-arc welding in naval shipbuilding. Weld residual stresses often lead to increased distortion, and reduction of fatigue life. Quantitative 3D nondestructive neutron diffraction measurements are vital to fully understand the complexity of this welding procedure and their influence on the weld integrity. This paper presents preliminary study of mechanical properties and residual stresses of the welds and their influence on the distortion and fatigue performance. Residual stress measurements were conducted by neutron diffraction at the OPAL reactor on the strain scanner KOWARI. The challenges of the project will be discussed and future planes will be presented.
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    Neutron diffraction residual stress measurements of welds made with pulsed tandem gas metal arc welding (PT-GMAW)
    (Cambridge University Press, 2014-11-10) Paradowska, AM; Larkin, N; Li, H; Pan, Z; Shen, C; Law, M
    Pulsed tandem gas metal arc welding (PT-GMAW) is being developed to increase productivity and minimise weld-induced distortion in ship-building. The PT-GMAW process was used in pulse–pulse mode to butt-weld two different strength and thickness steels; the residual stress and hardness profiles of the welds are reported and correlated. © International Centre for Diffraction Data 2014
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    Neutron optics upgrades to the residual stress diffractometer, KOWARI
    (Materials Research Forum LLC, 2016-07-03) Reid, M; Olsen, SR; Luzin, V; New, M; Booth, N; Clowes, D; Nguyen, T; Franceschini, F; Ogrin, A; Pangelis, S; Paradowska, AM; Larkin, N; Pan, Z; Hoye, N; Suzuki, H
    In the last 5 years a number of significant enhancements have been implemented on the neutron beam strain scanner Kowari at the OPAL reactor in Sydney Australia. These changes have resulted in reduced beam time losses when conducting experiments due to sample and stage alignment, and optics and sample changes. There have been 3 projects, starting in 2011 with a new manual slit system design and collision recovery system, in 2013 with a series of radial collimators and finally with the delivery. © The Authors