Microstructure of in-situ TiC particle reinforced
titanium alloy matrix composites①
titanium alloy matrix composites①
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Abstract: TiC particle reinforced titanium alloy matrix composites with different aluminum content was prepared by the XDTMmethod. The constitute phase and the microstructure of the composites were studied by XRD and SEM. The results show that the calculated lattice parameter of TiC there exists a diffraction peak shift for TiC, which may be due to the vacancies of C in TiC. The stoichiometry of TiC is Ti62C38. There exist two different kinds of TiC in the composites:
dendritic primary TiC and short bar-shape eutectic TiC, respectively. Although TiC of macrostructure is homogeneously distributed in the matrix, the eutectic TiC of microstructure mainly segregates at the grain boundary, especially at the triangular grain boundaries. The aluminum content has a great influence on the morphology of TiC. With increasing aluminum content up to 25%, the size of TiC becomes small although it is still in dendrite or short bar-shape. When the aluminum content is more than 35%, TiC is changed into thin plate or particle and the size is about 2~5μm.
dendritic primary TiC and short bar-shape eutectic TiC, respectively. Although TiC of macrostructure is homogeneously distributed in the matrix, the eutectic TiC of microstructure mainly segregates at the grain boundary, especially at the triangular grain boundaries. The aluminum content has a great influence on the morphology of TiC. With increasing aluminum content up to 25%, the size of TiC becomes small although it is still in dendrite or short bar-shape. When the aluminum content is more than 35%, TiC is changed into thin plate or particle and the size is about 2~5μm.
Key words: TiC; titanium matrix composites; microstructure; XDTM