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分别采用纳米SiC晶须(SiCW)、SiC颗粒(SiCP)及SiCW与SiCP共同增韧ZrB2陶瓷,在1950℃、20 MPa压力、氩气气氛下热压烧结制备了致密的SiC/ZrB2陶瓷材料。研究了SiCW和SiCP的添加量对于SiC/ZrB2陶瓷材料的显微结构、力学性能的影响,并分析了SiCW和SiCP对ZrB2陶瓷力学性能影响的协同作用和增韧机制。结果表明:含15 vol%SiCW的复合材料的韧性达到8.08 MPa.m1/2,含15 vol%SiCP的复合材料的韧性达到8.515MPa.m1/2,共同添加15 vol%SiCW和15 vol%SiCP的复合材料的韧性最高达到9.03 MPa.m1/2。SiC/ZrB2复合材料强度和韧性提高的原因在于SiCW和SiCP抑制ZrB2晶粒长大,促进ZrB2的致密化,此外,SiCW和SiCP的协同作用也有助于材料韧性的提高。
ZrB2 ceramics were toughened with SiC whiskers (SiCW), SiC particles (SiCCP), SiCW and SiCP, respectively. The dense SiC / ZrB2 ceramics were prepared by hot pressing sintering at 1950 ℃ and 20 MPa under argon atmosphere. The effects of addition amount of SiCW and SiCP on the microstructure and mechanical properties of SiC / ZrB2 ceramics were investigated. The synergistic effect and toughening mechanism of SiCW and SiCP on the mechanical properties of ZrB2 ceramics were also studied. The results show that the toughness of the composites containing 15 vol% SiCW reaches 8.08 MPa.m1 / 2, the toughness of composites containing 15 vol% SiCP reaches 8.515 MPa.m1 / 2, 15 vol% SiCW and 15 vol% SiCP The toughness of the composites reaches up to 9.03 MPa.m1 / 2. The reason for the increase of strength and toughness of SiC / ZrB2 composites is that SiCW and SiCP inhibit the growth of ZrB2 grains and promote the densification of ZrB2. In addition, the synergistic effect of SiCW and SiCP also contributes to the improvement of toughness.