【摘要】 由平均粒径为0.2μm的TiC,TiN细粉,经1430℃,1h真空烧结制备了Ti(C,N)基金属陶瓷。由扫描电镜和强度、硬度测量研究了 金属陶瓷的微观结构和性能。原料粉末以聚氧乙烯十二烷基醚为分散剂,蒸馏水为液体介质,溶液pH值保持在6～7之间,并使用超声波分 散,悬浮液过筛后烘干。扫描电镜分析表明:经分散后的粉末颗粒团聚较少、分散良好。分散后细粉以相同工艺制备得Ti(C,N)基金属陶瓷。 与未分散细粉烧结体对比表明:由分散细粉获得的金属陶瓷的硬度、抗弯强度均优于未分散细粉制备的烧结体,前者的硬度HRA为90.2,抗弯 强度为2108MPa;后者分别为89和1983MPa,其微观结构特征为存在较多的细小均匀的黑芯白壳包覆层结构。细粉分散后,颗粒大小的分 布较均匀而影响了液相烧结中的溶解析出过程,这是金属陶瓷微观结构和性能得到改善的重要原因。更多还原

【Abstract】 Ti（C,N）-based cermet was prepared from TiC, TiN fine powder with the size of 0.2 μm by sintering in vacuum at （1 430 ℃） for 1 h. Microstructure and mechanical properties of the cermet were characterized by scanning electron microscope （SEM） and measurements of hardness and bending strength. The fine powder prepared was dispersed in dispersing water solution by ultrasonic stirring with pH value of solution up to 6—7. SEM observation reveals that powder inhibits agglomeration effectively and dispersed well after dispersing process. Ti（C,N）-based cermet was fabricated by dispersed fine powder with the same sintering process. Compared with cermet prepared by un-dispersed fine powder, the cermet prepared by dispersed powder exhibits better hardness H_RA and bending strength. H_RA of former is 90.2 and beading strength is 2 108 MPa, while it is 89 and （1 983 MPa） for the latter respectively. SEM shows large amounts of smaller core-rim microstructure. The well-proportioned distribution of grain size of fine powder after dispersed affects the dissolution and precipitation reaction of sintering, which is considered as the primary reason for the improvement of cermet mechanical properties.更多还原