摘要
常压烧结制备了Al_2O_3和20%ZrB_2/Al_2O_3(质量分数)复合陶瓷,用XRD和金相显微镜、SEM分析了其相组成、微观结构、断裂形貌,并用压痕法计算了陶瓷的断裂韧性。结果表明:Al_2O_3陶瓷自1500℃开始其相对密度超过99%,维氏硬度达到18 970 MPa,断裂韧性为(5.2±0.3)MPa·m^(1/2);20%Zr B_2/Al_2O_3复合陶瓷在1450℃时相对密度超过98%,维氏硬度达到18 070 MPa,断裂韧性为(6.7±0.2)MPa·m^(1/2)。微观形貌观察表明,ZrB_2/Al_2O_3复合陶瓷韧性的增加是由于弥散分布的ZrB_2在Al_2O_3陶瓷基体中起到遏制裂纹扩展和钉扎双重作用的结果。
The Al_2O_3-ZrB_2 nanocomposite ceramics were prepared and the mechanical properties of the process parameters＇ effect were studied.The results show that for various applied sintering temperatures of Al_2O_3 ceramics,a maximum Vickers hardness of 18 970 MPa and high reliability are attained at 1500 ℃ and at atmosphere sintering.The fracture toughness is（5.2±0.3） MPa·m^1/2.In addition,the sample is not well densified at the sintering temperature.Scanning electron microscopy（SEM） shows that fine Zr B2 particles disperse and are pinned at grain boundaries to inhibit grain boundary movement effectively.While larger Zr B_2 particles distribute between A1_2O_3 particles uniformly and occupy Al_2O_3 particles growing space to hinder the matrix grains,which greatly promote the densification of the ceramic and improve the microstructure.20% Zr B_2/Al_2O_3 composite ceramics exhibit a relative density above 98% at（450 ℃,Vickers hardness of 18 070 MPa,and fracture toughness of（6.7±0.2） MPa·m^1/2 Fracture morphology indicates that trans-granular fracture occurs in the nanocomposite ceramic with high toughness.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2016年第7期1714-1718,共5页
Rare Metal Materials and Engineering
基金
Natural Science Foundation of Qinghai Province Science and Technology Department(2012-Z-924Q)
the Postdoctoral Research Fund of Lanzhou University of Technology
关键词
常压烧结
纳米氧化铝陶瓷
纳米复相陶瓷
增韧
atmospheric sintering
nano alumina ceramic
nanocomposite ceramics
toughening
