摘要
本文采用恒沸腾水解法制备了颗粒度均一的亚微米晶ZrO2(Y2O3)粉体,并以其为增韧相,在高温(1350℃)超高压(5GPa)条件下制备ZrO2(Y2O3)+SiC+金刚石的聚晶烧结体(PCD)。用XRD、SEM背散射分析、冲击韧性测定和磨耗比测定研究了不同含量Y2O3稳定的ZrO2粉体对SiC-金刚石聚晶烧结体结构及机械性能的影响,结果表明:ZrO2(Y2O3)粉体中Y2O3含量<2.2mol%时,ZrO2以四方t相+单斜m相的混合相形式存在于烧结体的结合剂基体上,t相量随Y2O3含量增加而增加,对SiC-金刚石聚晶烧结体的增韧来源于相变增韧和微裂纹增韧的叠加,当Y2O3含量>2.2mol%时,ZrO2以100%t相存在,增韧机制为相变增韧。在2.0mol%~2.2mol%Y2O3含量范围内,PCD可获得较高的磨耗比和冲击韧性。
Abstract Submicrocrystalline ZrO 2 (Y 2O 3) powder with homogeneous particle sizes is prepared by boilinghydrolysis method. SiC bonded polycrystalline diamond (PCD) toughed with ZrO 2 (Y 2O 3) is sintered at high temperature (1350℃) and ultra high pressure (5Gpa). The effects of Y 2O 3 content on the phase structure and the mechanical properties of PCD are investigated by XRD, SEM, impact toughness and G ratio measurements. The results show that the phase composition of ZrO 2 is tetragonal phase and monoclinic phase with Y 2O 3 content less than 2.2mol% . The toughness increasing comes from phase transformation and toughening by microcracks. The amount of t ZrO 2 increases as the Y 2O 3 content increasese 100% t ZrO 2 is retained with Y 2O 3 content more than 2.2mol%. The toughness is only caused by t m phase transformation.PCD has high grinding ratio and high
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
1998年第2期156-159,共4页
Journal of Synthetic Crystals
基金
国家自然科学基金