Browsing by Subject "temperature gradient"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Phase field simulation of dendritic microstructure in additively manufactured titanium alloy
    (Elsevier, 2019-01) Zhang, Jing; Wu, Linmin; Zhang, Yi; Meng, Lingbin; Mechanical and Energy Engineering, School of Engineering and Technology
    Additive manufacturing (AM) processes for metals, such as selective laser sintering and electron beam melting, involve rapid solidification process. The microstructure of the fabricated material and its properties strongly depend on the solidification. Therefore, in order to control and optimize the AM process, it is important to understand the microstructure evolution. In this work, using Ti-6Al-4V as a model system, the phase field method is applied to simulate the microstructure evolution in additively manufactured metals. First, the fundamental governing equations are presented. Then the effects of various processing related parameters, including local temperature gradient, scan speed and cooling rate, on dendrites’ morphology and growth velocity are studied. The simulated results show that the dendritic arms grow along the direction of the heat flow. Higher temperature gradient, scan speed and cooling rate will result in small dendritic arm spacing and higher growth velocity. The simulated dendritic morphology and arm spacings are in good agreement with experimental data and theoretical predictions.
  • Thumbnail Image
    Item
    Phase Field Simulation of Dendritic Solidification of Ti-6Al-4V During Additive Manufacturing Process
    (Springer, 2018-10) Wu, Linmin; Zhang, Jing; Mechanical and Energy Engineering, School of Engineering and Technology
    In this study, the phase field method is applied to simulate the phase transformation of Ti-6Al-4V from liquid phase to solid phase during solidification. The simulated results show the dendritic arms grow along the direction of the heat flow. Droplets are found formed inside the dendrites. Solute enriches in the liquid near the dendritic tips and between the dendritic arms. The effects of various processing parameters, including local temperature gradient, scan speed, and cooling rate, on dendrites morphology and growth velocity are studied. The results show that the higher temperature gradient, scan speed, and cooling rate will result in smaller dendritic arm spacing and higher growth velocity. The simulated dendritic morphology and arm spacings are in good agreement with experimental data and theoretical predictions.