2016 Volume 57 Issue 10 Pages 1691-1697
The effects of a new TRIPLEX heat treatment on the microstructure and the mechanical properties of in situ synthesized (TiB+La2O3)/IMI834 composite (TMCs) were studied. The microstructures and the morphology of reinforcements after heat treatment were characterized by optical microscopy, scanning electron microscopy (SEM), electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM). The martensite variation was in situ observed in the processing of TRIPLEX heat treatment by confocal laser scanning microscope (CLSM). The results showed that the microstructure of specimens after TRIPLEX heat treatment exhibits laminar structure with high aspect ratio. The percent of low angle boundaries of TMCs treated by TRIPLEX heat treatment and β heat treatment is about 22.71% and 25.32%, respectively. Compared with β heat treatment, the ductility of titanium matrix composites after TRIPLEX heat treatment was improved significantly. Tiny perpendicular cracks on TiB reinforcement and the crack initiating in matrix were in situ observed at the same time by CLSM during tensile test.