莫来石晶须加入量对莫来石制品性能的影响

Effect of mullite whisker addition on the properties of mullite products

以莫来石、黏土和α-氧化铝微粉为主要原料,分别添加0、1%、2%莫来石晶须,1600℃烧结3 h后制得莫来石制品,研究莫来石晶须加入量对莫来石制品物相组成、显微结构和性能的影响。结果表明:随着莫来石晶须加入量的增加,细小的二次莫来石穿过晶界向莫来石晶须跃迁的几率增加,使莫来石晶须快速长大呈长柱状并交错互锁,提高试样的致密程度和强度,降低试样的热膨胀性和高温蠕变性;确定出莫来石晶须加入量为2%时莫来石制品的各项性能最佳。

Mullite products were prepared by using mullite,clay,andα-alumina micropowder as the main raw materials and adding 0,1%and 2%mullite whisker respectively under the sintering for 3 hours at 1600℃,followed by a study on the effect of mullite whisker addition on the phase composition,microstructure and properties of mullite products.The results showed that as the addition of mullite whisker increases,odds are higher that the fine secondary mullite transitions across the grain boundary into mullite whiskers,allowing the mullite whisker to grow rapidly into long columns and stagger and interlock with each other,improving the sample's density and strength,and reducing its thermal expansion and high-temperature creep properties.Therefore,2%was defined as the best addition of mullite whiskers to achieve the top performance of mullite products.