纳米SiC晶须和SiC颗粒混合增韧ZrB2陶瓷性能

分别采用纳米SiC晶须(SiC_W)、SiC颗粒(SiC_P)及SiC_W与SiC_P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SiC_W和SiC_P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SiC_W和SiC_P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% SiC_W 的复合材料的韧性达到8.08 MPa·m1/2，含15 vol% SiC_P的复合材料的韧性达到8.515MPa·m1/2，共同添加15 vol% SiC_W和15 vol%SiC_P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SiC_W和SiC_P抑制ZrB₂晶粒长大，促进ZrB₂的致密化，此外，SiC_W和SiC_P的协同作用也有助于材料韧性的提高。

Properties of ZrB_2 ceramics reinforced by SiC nanowhiskers and SiC particles

SiC/ZrB2 composites reinforced by SiC nanowhiskers (SiCW ) and SiC particles (SiCP) were prepared by a hot-pressing process at 1950℃ under 20 MPa in a flow argon atmosphere. The effects of SiCW and SiCP on microstructures，mechanical properties of SiC/ZrB2 composites were investigated. The results showed that the fracture toughnesses of SiC/ZrB2 composites with 15 vol% of SiC Wand with 15 vol% of  SiCP were 8.08 MPa· m1/2 and 8.515 MPa·m1/2，respectively. The fracture toughness of the SiC/ZrB-composites with both 15 vol% of SiCW and 15 vol% of SiCP reached 9.03 MPa·m1/2. SiCW and SiCP effectively improved the densification of SiC/ZrB2 composites,and limited the coarsening of ZrB2 grains，which was in favor of improving the bending strength and fracture toughness of the SiC/ZrB2 composites. Furthermore，the synergistic effect of SiCW and SiCP favored the increase of the toughness.