氧化铝预制体烧结温度对GI-Ⅱ型渗透陶瓷性能的影响

Different sintering temperature of preform and relative properties of interpenetrating alumina-glass ceramic composite.

目的 :本实验旨在研究预制体烧结温度对最终熔融渗透氧化铝 -玻璃陶瓷复合体 (GI -Ⅱ型渗透陶瓷 )相关性能的影响。方法 :氧化铝浆料涂粉涂塑成长条状杆状试件 ,分别在 10 5 0、110 0、115 0、12 0 0℃烧结 ,然后在112 5℃渗入玻璃 ,试件研磨成 1.9mm× 6 .5mm× 2 5mm大小 ,然后测三点弯曲强度。记录条状试件在制作过程的收缩。结果 :预制体烧结温度升高 ,使渗透陶瓷收缩从 0 .2 0 4%增大到 0 .418% ,但是并未明显提高陶瓷强度。各组强度值分别为 (36 3 .80± 87.90 )MPa ,(380 .40± 5 5 .10 )MPa ,(36 1.2 0± 5 3 .2 0 )MPa ,(388.40± 82 .80 )MPa ,Weibull模数分别是 4.41,6 .88,6 .35 ,4.49。 12 0 0℃组强度稍高 ,但无统计学意义。结论 :从材料收缩小和强度高的要求选择 ,氧化铝预制体烧结温度可选在 110 0℃～ 115 0℃。

Objective:Melt-infiltration technique can be used to fabricate interpenetrating phase composite, during which, preform should be first formed and then be infiltrated.This study was designed to determine the effect of preform sintering temperature on relative properties of final melt-infiltrated alumina-glass ceramic composites.Methods:Alumina slurry was slip-cast in jig to prepare bar-shape samples.The samples were sintered at 1050℃、1100℃、1150℃、1200℃ for 2 hours,respectively.After cooling, special glass was infiltrated to the sintered preform at 1125℃ for 6 hours and cooled.The samples was ground to 1.9mm×6.5mm×25mm.Then bend strength values were obtained by 3-point bending test.Length of bars were also recorded before sintering and after infiltration.Result:The result indicated the rise of preform sintering temperature increased shrinkage of infiltrated ceramic composite from 0.204% to 0.418%.However,strength didn't show such significant trend.The strength values were (363.80±87.90)MPa,(380.40±55.10)MPa,(361.20±53.20)MPa,(388.40±82.80)Mpa,respectively and Weibull moduli were 4.41,6.88,6.35,4.49,respectively.Composite made of preform sintered at 1200℃ turned out a little high but no statistically difference.Conclusions:It is advisable to keep alumina preform sintering temperature not lower than 1100℃ in favor of strength.However,in terms of shrinkage rate,the maximum temperature should be not higher than 1150℃. [