摘要
采用放电等离子烧结(SPS)方法制备了金刚石颗粒(平均粒径为12μm、25μm及50μm)以20%的体积比弥散WC-10wt%Co硬质合金的致密复合物,为防止金刚石颗粒的氧化和石墨化,用高温化学反应方法在其表面生成了一层牢固结合的纳米尺寸的碳化硅保护膜。所得烧结体的相对密度均可达到98%。弥散金刚石颗粒基本保持了基体的高硬度,但是使复合物的断裂韧性得到了显著提高,金刚石粒度为50μm时,韧性高达17.8MPa·m1/2。沿金刚石颗粒周围可以清晰地观察到裂纹偏转及停止现象。金刚石粒度的变化对力学性能的影响不很明显。
Diamond particles, with average particle sizes of 12μm, 25μm and 50μm, were mixed with WC-10 wt%Co in a 20% volume fraction and densified by using SPS method. Before mixing, the diamond was coated by nanometer sized SiC layer against oxidation and graphitization. The relative density of all composites reached 98%. The Vickers hardness did not differ so much from the matrix hardness of WC-10 wt%Co by the dispersing diamond. However, the indentation toughness remarkably increased to 17.8 MPa·m1/2 with 50μm diamond dispersion. Crack deflection and block were clearly detected around diamond particles. The variation of diamond particle size did not affect the mechanical properties of the composite too much.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2004年第1期51-55,共5页
Acta Materiae Compositae Sinica
关键词
金刚石
SIC涂层
SPS
WC-CO
韧性
Cobalt
Cracks
Graphitization
Inorganic coatings
Mechanical properties
Oxidation
Silicon carbide
Sintering
Toughening
Tungsten carbide
Volume fraction
