The Al4SiC4-Al4O4C composites were synthesized using 1:6.5:2.6 of molar ratio of kaolinite grog powder, carbon black, and aluminum powder as basic formulation, fixing the additions of kaolinite grog powder and carbon black,varying aluminum powder addition to make its proportion from 2.6 to 3.9,5.5 ,7.0,8.6, and 10.4, respectively,adding phenolic resin as binder, absolute alcohol as dispersant, mixing well, pressing, drying ,firing at 1 700 ℃ for 2 h in a corundum tubular furnace in flowing argon.The effect of Al addition on phase composition and microstructure of Al4SiC4-Al4O4C composites was investigated by DTA-TG,XRD, and SEM.The results show that: (1)in a certain degree, more Al4SiC4 forms with Al powder addition increasing;(2)the formed Al4SiC4 has two morphologies, namely, sheet and block, and their particle sizes are 5-15 μm and 10-20 μm, respectively; (3) the At powder addition increase has little effect on the grain shape and size of Al4SiC4; (4)the formed Al4O4C mainly distributes on the surface of the Al4 SiC4 grains with irregular shape and particle size below 1 μm,and some of them bond together.%将高岭石熟料粉、炭黑粉和金属铝粉按n(Al2O3)∶n(C)∶n(Al)=1∶6.5∶2.6配料作为基料,保持高岭石熟料粉和炭黑的量不变,改变金属铝粉的量,使n(Al)从2.6分别增加到3.9、5.5、7.0、8.6和10.4,以酚醛树脂为结合剂,无水酒精为分散剂,混匀后压制成型,坯体试样干燥后,在刚玉质管式炉内,氩气气氛下,于1 700℃保温2 h制备了Al4SiC4-Al4O4C复合材料.利用DTA-TG、XRD和SEM等测试技术,研究了铝粉加入量对该材料相组成和显微结构的影响.结果表明:在一定范围内随着金属Al粉加入量的增加,Al4SiC4产物的含量也会相应的增加.试样中生成的Al4SiC4有片状和块状两种形貌,粒径分别在5～15和10～20 μm之间.金属Al粉添加量的增加,对Al4SiC4晶粒形状和粒径影响不大;合成的Al4O4C粒径一般在1μm以下,主要分布在Al4SiC4晶粒表面,形状无规则,部分还粘结在一起.
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