Interfacial reaction in SiCf/C/TiAl matrix composites
Xiaoyu Li, Wei Zhang
Abstract
SiCf/C/TiAl matrix composite is a kind of high temperature structural material with wide application prospects because of its good properties. It can replace traditional high temperature alloys used in aerospace. This study characterized the reaction products of the SiC/C/Ti interfacial reaction layer. The mechanism of diffusion -solution-reaction was used to show the process of the interface products. SiCf/C/TiAl composites were prepared by matrix coated fiber (MCF) method combined with hot isostatic pressing. The interfacial reaction products of SiCf/C/TiAl matrix composites were studied employing scanning electron microscopy (SEM) and transmission electron microscopy (TEM) with EDX. To study the effect of preparation temperature on the interfacial reaction, two kinds of processing parameters of composites were used. The results showed that in the three reaction products TiC, Ti2AlC, and Ti5Si3, Ti5Si3 was finally formed under 1253 K/150 MPa/1 h. TiC is close to the C coating, Ti5Si3 is close to the matrix alloy, and there is the columnar Ti2AlC phase between the TiC layer and Ti5Si3 layer. By combining the interface reaction energy spectrum curve and electron diffraction spectrum, it can be determined that the reaction produces two products, TiC and Ti2AlC under1223 K/160 MPa/1 h, respectively. Besides a thin C coating near the fine TiC layer shows amorphous characteristics.