Interface and Wear Resistance of SiC Ceramic Column Grid Array Reinforced High-Chromium Cast Iron Composite Pretreated with TiH2

Reaction-bonded SiC ceramic columns were coated by titanium hydride (TiH2) powder paste firstly, and then pretreated in a vacuum at 1000 or 1400 oC for 20 min. After that, the pretreated SiC ceramic columns were fixed on a graphite plate. Subsequently, a kind of SiC ceramic column grid array reinforced high-chromium cast iron composites, with high macro-uniformity, reliability and designability of the ceramic reinforcements, were fabricated by metal casting. The microstructure analysis on the ceramic coating and the ceramic/metal interface of the SiC/iron composite reveals that a reliable metallic composite coating can be formed on the SiC surface after the pretreatment at 1400 oC which was proved to be a better pretreatment temperature. The as-formed coating would not be dissolved during the metal casting process, and the interfacial reactions between SiC and iron were also restrained effectively, resulting in an excellent ceramic/metal interface without delamination after wear testing. Moreover, the wear resistances of the SiC/iron composites with different SiC ceramic contents are improved markedly in comparison with that of the metal matrix due to the effective additions of SiC ceramic columns.