摘要
采用热压工艺烧结制备了SiCW Ti(C ,N) Al2 O3(Y2 O3)陶瓷刀具复合材料。研究了不同烧结温度(16 0 0～ 175 0℃ )下 ,材料的致密度和力学性能 (断裂韧性KIC ,维氏硬度HV和抗弯强度σf)随晶须含量 (10 %～4 0 % )的变化关系 ;探讨了SiC晶须和Ti(C ,N)颗粒对Al2 O3基体的协同增韧机理。同时与SiCW Al2 O3陶瓷及Ti(C ,N) Al2 O3陶瓷作对比研究。结果表明 :SiCW Ti(C ,N) Al2 O3(Y2 O3)陶瓷材料在 175 0℃ ,晶须含量为 2 0 %时获得最佳的综合力学性能 :KIC =7 11MPa m1 2 ,HV =2 1 16GPa ,σf=82 0MPa ;明显高于SiCW 含量为 2 0 %的SiCW Al2 O3陶瓷和不加晶须的Ti(C ,N) Al2 O3陶瓷。第三相Ti(C ,N)颗粒的加入与晶须一起产生明显的迭加增韧效果 ,而且对SiCW 的各种增韧机制起到了促进作用。
SiC whiskers and Ti(C,N) particles toughened Al 2O 3 matrix ceramic composites for cutters were fabricated with hot pressing technique, with a certain amount of Y 2O 3 used as sintering aids to reduce the sintering temperature. The variations of the density and mechanical properties(i.e., fracture toughness K IC, Vickers hardness HV and flexural strength) of the specimens sintered at different temperatures from 1600-1750℃ versus the contents of SiC whiskers are studied. The synergistic toughening mechanisms of SiC whiskers and Ti(C,N) particles are discussed. Meanwhile, a comparative study of the SiC W-Ti(C,N)-Al 2O 3(Y 2O 3) composites is made against the 20% SiC W-Al 2O 3 and Ti(C,N)-Al 2O 3 composites fabricated simultaneously. The results show that: the optimal comprehensive mechanical properties of the SiC W-Ti(C,N)-Al 2O 3(Y 2O 3) ceramic composite are:K IC7.11MPa.m 1/2, HV21.16GPa, σ f820MPa,obtained at 1750℃ and with a 20 weight percentage loading of whiskers, which is obviously higher than the mechanical properties of the 20% SiC W-Al 2O 3 and Ti(C,N)-Al 2O 3 materials; and that SiC whiskers and Ti(C,N) particles produce a favorable synergistic toughening effect in the matrix, for the addition of Ti(C,N) particles facilitates the function of the various toughening mechanisms of SiC whiskers.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2004年第1期59-64,共6页
Journal of Materials Science and Engineering
