摘要
为了提高硼酸铝基陶瓷的强度和隔热性能,以Al_(2)O_(3)纳米粉和B_(2)O_(3)微粉为主要原料,采用叔丁醇基凝胶注模结合原位固相反应工艺制备硼酸铝多孔陶瓷,研究了Al、B物质的量比(分别为9∶2、9∶4和9∶6)、热处理温度(分别为1000、1200和1400℃)对硼酸铝多孔陶瓷性能的影响。结果表明:1)由于B_(2)O_(3)在高温下易挥发,过量的B_(2)O_(3)有利于硼酸铝晶须的生成;但过量太多会使生成的硼酸铝晶须过于粗大,导致试样致密度过高。2)热处理温度过低,硼酸铝晶须发育较差,试样致密度较低;而热处理温度过高,晶须之间会发生烧结致密化。3)当Al、B物质的量比为9∶4,热处理温度为1200℃时,硼酸铝晶须长径比较大,并相互交织形成三维网络结构;所得多孔陶瓷具有较小的体积密度(0.67 g·cm^(-3))、较低的热导率(室温下0.141 W·m^(-1)·K^(-1))和较高的常温耐压强度(6.23 MPa)。
In order to improve the strength and thermal insulating performance,porous aluminum borate ceramics were fabricated by tert-butyl alcohol-based gel casting combined with in situ solid state reaction technology with Al_(2)O_(3) nanopowder and B_(2)O_(3)micropowder as raw materials.Effects of aluminum/boron molar ratios(9∶2,9∶4 and 9∶6)and heat treatment temperatures(1000,1200,and 1400℃)on the properties of porous aluminum borate ceramics were investigated.The findings are as follows.(1)Because B_(2)O_(3)volatiles easily at high temperatures,excessive B_(2)O_(3)is conducive to the formation of aluminum borate whiskers.However,too much B_(2)O_(3)leads to the formation of over-thick aluminum borate whiskers,resulting in over-high density.(2)Low heat treatment temperatures are not suitable for the development of aluminum borate whiskers,resulting in low bulk density,while over-high heat treatment temperatures can lead to sintering densification between whiskers.(3)When the aluminum/boron molar ratio is 9∶4 and the heat treatment temperature is 1200℃,the generated aluminum borate whiskers show a large length/diameter ratio and interlock with each other to form a three-dimensional network structure.The obtained porous aluminum borate ceramic exhibits low density(0.67 g·cm^(-3)),low thermal conductivity(0.141 W·m^(-1)·K^(-1)at room temperature),and high cold compressive strength(6.23 MPa).
作者
李鑫
李昊明
张强
曹岳岐
刘幸儿
郭安然
Li Xin;Li Hao-ming;Zhang Qiang;Cao Yueqi;Liu Xing’er;Guo Anran(Key Laboratory of Advanced High-temperature Structural Materials,AECC Bejing Institute of Aeronautical Materials,Beijing 100095,China;不详)
出处
《耐火材料》
CAS
北大核心
2023年第4期277-280,共4页
Refractories
基金
国家自然科学基金(No.51872194)。
关键词
多孔陶瓷
硼酸铝晶须
凝胶注模
固相反应
隔热材料
porous ceramics
aluminum borate crystal whisker
gel casting
solid state reaction
thermal insulation materials
