Cr_(2)O_(3)添加量对SrAl_(12)O_(19)-Al_(2)O_(3)-ZrO_(2)复相陶瓷力学性能和微观结构影响

Effect of Cr_(2)O_(3) on Microstructure and Mechanical Properties of SrO-ZTA Composite Ceramics

以3Y-TZP、α-Al_(2)O_(3)、Sr(NO3)2为基础原料,掺杂了不同含量的Cr(NO_(3))_(3)·9H_(2)O,通过无压预烧和热等静压烧结结合的方式制备了SrO和Cr_(2)O_(3)共掺杂的ZTA复相陶瓷。研究了Cr_(2)O_(3)添加量对SrAl_(12)O_(19)-Al_(2)O_(3)-ZrO_(2)复相陶瓷微观结构和力学性能的影响。XRD衍射谱显示,随着Cr_(2)O_(3)添加量的增多,α-Al_(2)O_(3)和SrAl_(12)O_(19)的衍射峰向左偏移,晶胞参数逐渐增大。结合EDS分析推测,Cr_(2)O_(3)更偏向于进入SrAl_(12)O_(19)的晶格。微观结构显示,Cr_(2)O_(3)的加入促进了晶粒生长。随着Cr_(2)O_(3)添加量的增多,断裂韧性和抗弯强度先上升后下降。当Cr_(2)O_(3)掺杂量为0.50 wt.%时力学性能最佳,其显微硬度、断裂韧性和抗弯强度分别为18.45 GPa、6.9 MPa·m^(1/2)和910 MPa。

With 3Y-TZP,α-Al_(2)O_(3)and Sr(NO_(3))_(2)as raw materials,ZTA composite ceramics doped with SrO and Cr_(2)O_(3)were prepared by using the combination of pressureless pre-sintering and hot isostatic pressing sintering.Cr_(2)O_(3)was derived from Cr(NO_3)_3·9H_(2)O.The effect of Cr_(2)O_(3)on microstructure and mechanical properties of the SrO-ZTA composite ceramics was studied.With increasing content of Cr_(2)O_(3),the XRD diffraction peaks ofα-Al_(2)O_(3)and SrAl_(12)O_(19)shifted to the low angles,suggesting that the lattice parameters gradually increased.Combined with EDS analysis,it is speculated that Cr_(2)O_(3)entered the lattice of SrAl_(12)O_(19),positively affecting mechanical properties of the final composite ceramics.The doping of Cr_(2)O_(3)promoted grain growth of the composite ceramics.As the content of Cr_(2)O_(3)was increased,fracture toughness and flexural strength first increased and then decreased.When the Cr_(2)O_(3)content was 0.50 wt.%,microhardness,fracture toughness and flexural strength reached 18.45 GPa,6.9 MPa·m^(1/2)and 910 MPa,respectively.