Interfacial structure and mechanical properties of the Ta/Re layered composites prepared by chemical vapor deposition

A novel Ta/Re layered composites with high temperature resistance, low cost, light weight, and excellent mechanical properties has been prepared by chemical vapor deposition, for improving the comprehensive service performance of the aerospace engine nozzle materials. The interface structure, element distribution, and mechanical properties of the Ta/Re layered composites have been studied with scanning electron microscopy, energy dispersive spectroscopy, x-ray diffraction, and tensile testing machine. The results show that the structure of the Ta/Re layered composites is flat and smooth, uniform, and dense. Further, the interface joint is a serrated meshing structure, which tremendously improves the interface bonding properties. The high temperature (1600 degrees C) tensile strength of the heat-treated Ta/Vol. 30% Re layered composites is 125 MPa, which is 2.8 times and 56.3% higher than the commonly used nozzle materials C103 and Nb521, respectively, whereas the raw material cost is only about 46% of that of pure rhenium. The heat treatment process enhances the mutual diffusion behavior of the atoms in the interface diffusion layer, and increases the thickness of the diffusion layer, besides changing the mechanical properties of the material. When the heat treatment process is at 1800 degrees C x 1 h, the highest tensile strength at room temperature is 739.61 MPa, which is 42.76% higher than that in a deposited state. This work can provide a reference for the further research of the Ta/Re layered composites.