ZrO_2加入量对镁铝铬不烧砖性能的影响

Influences of ZrO_2 additions on properties of magnesia-alumina-chrome unfired brick

以电熔镁砂、高纯镁砂、α-Al2O3微粉和Cr2O3微粉为主要原料,研究了ZrO2加入量对镁铝铬不烧砖热膨胀性以及烧后试样常温性能及抗热震性的影响。结果表明:加入ZrO2可以减弱镁铝铬不烧砖试样在1 100～1 300℃时的线膨胀率增大趋势,并降低线膨胀系数的最大值。镁铝铬不烧砖烧后试样的烧后线变化率、显气孔率、常温抗折强度和耐压强度随着ZrO2加入量增加而逐渐增大;当ZrO2加入量(w)为6%时,镁铝铬不烧砖试样的抗热震性最好。

The specimens were prepared using fused magnesia,high purity magnesia,α-Al2O3 micropowder and Cr203 micropowder as main starting materials. Influences of ZrO2 additions on the thermal expansion property of magnesia-alumina-chrome unfired brick,the cold properties and thermal shock resistance of fired specimens were investigated. The results show that：adding ZrO2 slows the increasing trend of linear expansion rate of the unfired brick at 1100-1 300 ℃ and reduces the maximum value of the linear expan- sion coefficient; the change in dimensions, apparent porosity, cold modulus of rupture and crushing strength of the unfired bricks after firing increase with ZrO2 addition increasing;the unfired brick performs the best thermal shock resistance with 6 mass% of ZrO2.