Browsing by Subject "molten pool"

Now showing 1 - 2 of 2

3-Dimensional Finite Element Modeling of Selective Laser Melting Ti-6Al-4V Alloy
(University of Texas at Austin, 2014) Fu, C.H.; Guo, Y.B.
Selective laser melting (SLM) is widely used in making three-dimensional functional parts layer by layer. Temperature magnitude and history during SLM directly determine the molten pool dimensions and surface integrity. However, due to the transient nature and small size of the molten pool, the temperature gradient and the molten pool size are very challenging to measure and control. A 3-dimensional finite element simulation model has been developed to simulate multi-layer deposition of Ti-6Al-4V in SLM. A physics-based layer build-up approach coupled with a surface moving heat flux was incorporated into the modeling process. The melting pool shape and dimensions were predicted and experimentally validated. Temperature gradient and thermal history in the multi-layer build-up process was also obtained. Furthermore, the influences of process parameters and materials on the melting process were evaluated.
Simulation of the Thermal Behavior and Analysis of Solidification Process During Selective Laser Melting of Alumina
(University of Texas at Austin, 2018) Zhang, Kai; Liu, Tingting; Liao, Wenhe; Zhang, Changdong; Zheng, Yi; Shao, Huang
Selective laser melting (SLM) has rapidly developed in the past decade. High precision-complex ceramics parts can be directly fabricated using this technology. To study the thermal behavior of molten pools in the selective laser melting of alumina （Al2O3）, we established a three-dimensional model based on ANSYS. Then, combined with simulation results, the physical phenomena during the rapid solidification process were discussed. The simulation results showed that the laser power and scanning speed exerts a marked influence on the maximum temperature, liquid lifetime, dimensions, and temperature gradient of the molten pool. Owing to the different temperature gradients in the molten pool, the thermal capillary force on the free surface varies. As a result, a slight difference exists between the stripy solidification structures. Different orientations of columnar crystals can be obtained. The underlying mechanism controls the direction of the temperature gradient with suitable processing routes, such as decreasing the scanning speed.