Spark plasma sintering of novel ZrB2–SiC–TiSi2 composites with better mechanical properties

摘要: We report here the development of ultrafine grained ZrB2-SiC composites using TiSi2 as sintering aid and spark plasma (SPS) processing technique. It was observed that presence improved sinterability composites, such near theoretical densification (99.9%) could be achieved for ZrB2-18 wt.% SiC-5 after SPS at 1600 degrees C 10 min 50 MPa. Use innovative multi stage (MSS) route, which involved holding samples lower (intermediate) temperatures some time before final temperature, while keeping net to min, allowed attainment full SiC-2.5 a still temperature 1500 30 TEM observations, revealed anisotropic ZrB2 grains with faceted grain boundaries intergranular regions, suggested occurrence liquid phase in TiSi2. No additional detected XRD well TEM, confirmed absence any reaction. The developed possessed an excellent combination Vickers hardness indentation toughness, both increased increase content, ZrBi2-18 (SPS processed C) similar 20 GPa toughness 5 MPa m(1/2). use MSS composite resulted improvement up 27 high flexural strength 455 (C) 2011 Elsevier B.V. All rights reserved.