Fracture Behavior of Directionally Solidified Y₃Al₅O₁₂/Al₂O₃ Eutectic Fiber

Abstract

The strength and fracture of a directionally solidified Y3Al5O12/Al2O3 eutectic fiber were investigated. The fiber was grown continuously by an edge‐defined film‐fed growth technique. The microstructure was characterized using X‐ray diffraction, scanning electron microscopy, and energy‐dispersive spectroscopy. The tensile strength and Weibull's modulus of the eutectic fibers were determined in the as‐fabricated state and after extended thermal exposure at 1460°C in air. Fractographic analysis was used to identify and classify the strength‐limiting mechanisms. The fracture toughness and crack growth behavior were characterized by an indentation technique. A fracture mechanics analysis was also used to establish the relationships between surface flaw size, tensile strength, and fracture toughness of the fiber.

Comparative study on the luminescent properties of Y3Al5O12:RE3+ (RE: Eu, Dy) phosphors synthesized by three methods

“…The diffraction pattern of the samples showed that the formation temperature of YAG phase for three methods were 800 • C (CG method) and 900 • C (CP and SS methods), respectively. In the traditional solid-state (SS) synthesis of YAG using metal oxides as the starting materials, the crystallization of YAG was reported to begin above 1000 • C and the other metastable yttrium aluminates phases could also be observed at the same time [9]. However, here by using Al(NO 3 ) 3 ·9H 2 O instead of A1 2 O 3 as one of the starting materials in the SS method, the other component Y 2 O 3 oxide can be dissolved into nitrate, which is beneficial for mixing the reactants and lowering the crystallization temperature.…”

“…Several reports have proved that among the various factors to improve the performances of phosphors, synthesis method has appeared the most important [6][7][8]. Wide techniques have been reported to produce YAG phases such as solid-state synthesis [8,9], sol-gel [10] and citrate-gel process [11], coprecipitation method [12,13] and hydrothermal method [14], etc. In an earlier paper [15], we reported the influence of synthesis methods on the luminescence properties of YAG:Re (Re = Ce 3+ , Sm 3+ ,Tb 3+ ) phosphors.…”

Microstructural stability and orientation relationships of directionally solidified Al2O3-Er3Al5O12-ZrO2 eutectic ceramics up to 1600 °C

“…In addition, table 1 presents the interspacing However, for AEZ samples grown at higher rates and, therefore, with finer microstructures, significant coarsening was observed. The coarsening was homogeneous throughout the sample cross-sections and there was no evidence of exaggerated localized coarsening, contrary to that observed in binary Al 2 O 3 -Er 3 Al 5 O 12 [16] and Al 2 O 3 -Y 3 Al 5 O 12 [18,26] eutectics.…”

Preparation of Y3Al5O12:Cr powders by microwave-induced combustion process and their luminescent properties

“…YAG and YAG-based phosphors have been prepared by several techniques, such as solid-state reaction [8,9], sol-gel [10], coprecipitation method [11,12], and hydrothermal method [13]. In this study, we used a new method called microwave-induced combustion to synthesise YAG:Cr powder.…”