Browsing by Subject "functionally graded materials"

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    Segregation phenomena during deposition of functionally graded zirconia-based ceramics with Stellite 21 on a steel substrate
    (Elsevier, 2020-02) Rao, Harish; Jaysekara, Indumini; Dutta, Bhaskar; Maurice, David; Pediatrics, School of Medicine
    This report describes the co-deposition of ceramic-metal systems based upon yttria-stabilized zirconia, and gadolinium zirconate, with Stellite 21 via laser direct energy deposition (LDED). The segregation of un-melted ceramic particles and the depletion of stabilizing dopants observed in previous work [1] is replicated. The segregation of un-melted ceramic particles results in a surface coating which prevents further deposition. The depletion of stabilizing dopants from the ceramics results in phases which are known to lack stability at the high temperatures expected in such applications. We provide a mechanistic explanation for the compositional segregation phenomenon, which suggests that the pairing of lanthanide series – based ceramics such as yttria-stabilized zirconia and gadolinium zirconate with transition metal alloys such as Inconel and Stellite may be difficult to effectively utilize in a functionally graded coating.
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    Simulation and Validation of Three Dimension Functionally Graded Materials by Material Jetting
    (Elsevier, 2018-08) Salcedo, Eduardo; Baek, Dongcheon; Berndt, Aaron; Ryu, Jong Eun; Mechanical Engineering, School of Engineering and Technology
    The goal of this work is to validate the material models for parts created with a Material Jetting 3-dimensional printer through the comparison of Finite Element Analysis (FEA) simulations and physical tests. The strain maps generated by a video extensometer for multi-material samples are compared to the FEA results based on our material models. Two base materials (ABS-like and rubber-like) and their composites are co-printed in the graded tensile test samples. The graded islands are embedded in the rubber-like test specimens. The simulations were conducted utilizing previously fitted material models, a two-parameter Mooney-Rivlin model for the elastic materials (Tango Black+, DM95, and DM60) and a bilinear model for the rigid material (Vero White+). The results show that the simulation results based on our material models can predict the deformation behaviors of the multi-material samples during a uniaxial tensile test. Our simulation results are able to predict the maximum strain in the matrix material (TB+) within 5% error. Both global deformation pattern and local strain level confirm the validity of the simulated material models.