Al_2O_3/Ni金属陶瓷显微结构和力学性能的研究  

Microstructure and Mechanical Properties of Al_2O_3/Ni Cermet

作　　者：李国军[1] 黄校先[2] 郭景坤[2] 

机构地区：[1]大连铁道学院材料科学与工程系,大连116028 [2]中国科学院上海硅酸盐研究所,上海200050

出　　处：《无机材料学报》2004年第3期546-552,共7页Journal of Inorganic Materials

基　　金：国家973项目(G2000067204-2)

摘　　要：采用包裹工艺和热压工艺制备了Al_2O_3/Ni金属陶瓷。在1450℃热压Ni包裹Al_2O_3复合粉体得到相对密度>98％的金属陶瓷,当温度>1400℃时,随着Ni含量的增加致密度下降.Ni颗粒位于三角晶界,随着含量的增加,断裂方式由沿品转为穿晶断裂;在Al_2O_3基体中引入Ni颗粒能够降低晶粒尺寸,提高强度和韧性.与单相Al_2O_3的力学性能相比,综合力学性能较好的NA4金属陶瓷的抗弯强度和断裂韧性分别提高了19％和35％,分析了金属陶瓷的增强增韧机制.Ni-coated Al_2O_3 powders with different Ni content were prepared by the coating technique. The powders were sintered by hot-pressing, and Al_2O_3/Ni cermet obtained. Results show that the densification is enhanced with the increase of temperature, and when temperature is more than 1400℃, the densification is decreased with the increase of Ni content. Ni particles introduced in Al_2O_3 ceramic matrix can reduce grain sizes, enhance strength and toughness. Com- pared with single phase Al_2O_3 material, Al_2O_3/4vol% Ni cermet has flexural strength of 19% and fracture toughness of 35% enhanced. SEM photos of fracture surface show that the fracture model of the cermet changes from intergranular fracture to transgranular fracture with the increase of Ni content.

关 键 词：Al2O3/Ni金属陶瓷 致密度 显微结构 力学性能 

分 类 号：TB331[一般工业技术—材料科学与工程]