自增韧RE-α-sialon陶瓷的微观结构与力学性能  

MICROSTRUCTURE AND MECHANICAL PROPERTIES OF IN-SITU TOUGHENED RE-α-SIALON CERAMICS

作　　者：刘春凤[1] 任先武[2] 叶枫[1] 周玉[1] 

机构地区：[1]哈尔滨工业大学特种陶瓷研究所,哈尔滨150001 [2]中国电子科技集团公司第四十九所,哈尔滨150001

出　　处：《硅酸盐学报》2008年第8期1134-1139,共6页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金重点(50632020);黑龙江省杰出青年基金(JC200603)资助项目

摘　　要：选用不同离子尺寸的稀土氧化物单一或复合掺杂α-sialon陶瓷,系统研究了陶瓷的相组成、晶粒形貌、微观结构以及力学性能与稀土元素的类型的关系。结果表明:小尺寸Yb3+稳定的α-sialon陶瓷完全由等轴α-sialon相构成;当尺寸略大的Y3+部分替代或全部替代Yb3+时,出现长棒状晶粒,在三角晶界处出现少量晶间相,并在晶粒间存在连续的薄非晶膜。在大尺寸稀土离子(Sm3+,Nd3+)稳定的陶瓷中存在块状晶间相M'(RE2Si3–xAlxO3+xN4–x,RE代表稀土元素),在Nd-α-sialon中,还含有少量β-sialon相,使Nd-α-sialon材料的硬度略有下降,晶粒尺寸存在双峰分布使断裂韧性较高。Yb-和Dy-α-sialon晶粒尺寸为正态分布使韧性较低,Yb和Y复合掺杂可改善Yb-α-sialon的韧性。The α-sialon ceramics were prepared using single or dual rare-earth oxides as stabilizer. The effects of type of rare-earth element （RE） on the phase assemblages, grain morphology, mierostrueture and properties were investigated. The results reveal that ceramic doped with a smaller cation （Yb^3＋） is fully composed of equiaxial α-sialon while the morphology with elongated grains can be obtained by partially substituting Yb with Y as a modifying cation, accompanied by a few intergranular phases in triple-point pockets and continuous thin glassy film between the α-sialon grains. In the larger cation-doped ceramics （Sm^3＋ and Nd^3＋） there are a few block-like M′ （RE2Si3-xAlxO3＋xN4-x） phases and even β-sialon in the Nd-α-sialon ceramic, which causes the hardness to decrease slightly. Yb- and Dy-α-sialons have relatively lower toughness due to the normal distribution in grain size, whereas Y-, Sin-, Nd-′ and Yb/Y-α-sialons with bimodal distribution of grains size possess higher toughness.

关 键 词：Α-SIALON 稀土氧化物 微观组织:力学性能 

分 类 号：TQ174[化学工程—陶瓷工业]