摘要
以硼酚醛树脂(BPF)为基体,以纳米MgO、Al_2O_3和SiO_2(MAS)为成瓷填料,添加B_2O_3、Bi_2O_3或玻璃料等助熔剂,采用模压成型工艺制备MgO-Al_2O_3-SiO_2/硼酚醛(MAS/BPF)陶瓷化复合材料,研究助熔剂对MAS/BPF陶瓷化复合材料热稳定性、微观结构和物相转变的影响。结果表明:MAS/BPF陶瓷化复合材料在600~1000℃裂解2h后的尺寸收缩率为9%~14.5%,表现出良好的尺寸稳定性;TG热分析发现,助熔剂使MAS/BPF陶瓷化复合材料在1200℃时的残留率降低,但在900~1200℃的热稳定性提高。XRD和SEM分析结果显示,助熔剂能够显著降低陶瓷化反应温度。和B_2O_3、Bi_2O_3相比,玻璃料更有助于形成大量的液相,促进陶瓷化组分与裂解残余碳之间的反应,从而提高MAS/BPF陶瓷化复合材料在高温下的致密性和外形完整性。
MgO-Al_2O_3-SiO_2/boron phenolic（MAS/BPF）ceramifiable composites,based on ceramifiable fillers of nano MgO,Al_2O_3 and SiO_2（MAS）modified matrix boron phenolic resin（BPF）,were prepared with fusing agent of B_2O_3,Bi_2O_3 or glass frits by hot compression molding.The effects of fusing agent on the thermal stability,microstructure and phase-transition of MAS/BPF ceramifiable composites were studied.The results show that the dimensional shrinkage rate varies from 9% to 14.5% after pyrolysed at 600-1000 ℃ for 2h,indicating agreat dimensional stability.And TG analysis reveals that the fusing ageing reduces the char yields of MAS/BPF ceramifiable composites at 1 200 ℃,but leading to a higher thermal stability at 900-1 200 ℃.XRD and SEM manifest ceramic reaction occurs at lower temperature with the addition of fusing agent.Compared with B_2O_3 and Bi_2O_3,glass frits contribute to forming a large amount of liquid phase structure,which promotes the reaction between the porous carbon from the decomposed resin matrix and ceramifiable fillers,improving the density and dimensional stability at high temperatures of MAS/BPF ceramifiable composites.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2017年第1期60-66,共7页
Acta Materiae Compositae Sinica
基金
湖北省企业委托项目(20131f0069)
关键词
可瓷化碳基复合材料
硼酚醛树脂
助熔剂
热防护材料
残余物
ceramifiable carbon-based composite
boron phenolic resin
fusing agent
thermal protection material
residue
