材料期刊网

为了研究环氧树脂结合体系对浇注成型 Si3 N4结合 SiC 耐火材料性能的影响，以 SiC 颗粒（粗颗粒2．5～1．43 mm、中颗粒1．43～0．5 mm 和细颗粒0．5～0．2 mm）、SiC 细粉、SiC 微粉和 Si 粉为原料，水溶性环氧树脂、多胺类固化剂、2，4，6－三（二甲氨基甲基）苯酚促进剂为环氧树脂凝胶结合体系，采用浇注成型制备了Si3 N4结合 SiC 试样，研究了促进剂加入量（分别占环氧树脂质量的0、5％、10％、15％）、环氧树脂加入量（外加质量分数分别为1％、1．5％、2．5％和3％）及骨料配比（粗、中、细 SiC 颗粒质量比分别为202030、203020、253015、252520、302020和302515）对试样性能的影响。结果表明，随着体系中促进剂加入量的增多，固化反应速率加快，生坯的脱模强度小幅增大，烘后生坯强度降低；随着体系中环氧树脂加入量的增多，生坯的抗折强度逐渐增大，但烧后试样的体积密度降低，显气孔率增大，常温抗折强度和耐压强度逐渐降低，且烧后试样中主要为氮化硅和碳化硅晶相，不含其他杂质相；随着骨料中 SiC 粗颗粒比例的增多，浆料的流动值增大，当粗、中、细颗粒质量比为302515时，试样的性能最优。综合考虑浇注性能，环氧树脂合适的外加质量分数为1．5％，促进剂合适的加入量为环氧树脂加入质量的5％，骨料中粗、中、细 SiC 颗粒的最佳质量比为302515。

To investigate the influence of epoxy resin bonding systems on properties of gel casting Si3 N4 bonded SiC refractories,Si3 N4 bonded SiC specimens were prepared using SiC particles (coarse parti-cles:2.5 -1.43 mm,middle particles:1.43 -0.5 mm,and fine particles:0.5 -0.2 mm),SiC fines,SiC mi-cropowders and Si powder as starting materials,and water soluble epoxy resin,multi-amine curing agents, and 2,4,6-tris (dimethylaminomethyl)phenol accelerator as the bonding system.The influences of the ac-celerator additions (0,5%,10%,and 15% of the epoxy resin addition),the epoxy resin additions (extra-adding 1%,1.5%,2.5%,and 3% by mass),and the aggregate gradation ratios (coarse middle fine =20 20 30,20 30 20,25 30 15,25 25 20,30 20 20,and 30 25 15,respectively,by mass)on the proper-ties of the specimens were studied.The results show that as the accelerator addition increases,the curing rate enhances and the demolding strength of the green body increases a little,but the dried strength of the green body decreases.As the epoxy resin addition increases,the modulus of rupture of the green body im-proves but after firing the bulk density decreases,apparent porosity increases,cold crushing strength and modulus of rupture decrease,and the main phases in the fired specimens are Si3 N4 and SiC without other impurities.As there are more coarse and middle particles in the aggregates,the flowability increases;the best property can be obtained when the ratio is 30 25 15.Considering the overall properties,the optimal epoxy resin addition is 1.5 mass%,the optimal accelerator addition is 5% of the epoxy resin addition and the optimal SiC particle gradation ratio in the aggregates is 30 25 15.