烧成制度对合成β-SiAlON-15R复相材料的影响

Influence of firing schedule on synthesis of β-SiAlON-15R composites

以硅粉、金属铝粉、氧化铝微粉为主要原料，在氮气气氛中分别于1500、1550和1600℃合成15-SiAlON（Z=2．5）和15R（Z=3）含量各为50％（w）的β-SiAlON-15R复相材料。利用TG-DSC和XRD研究了烧成制度对合成β-SiAlON-15R复相材料的影响。结果表明：（1）在500—550℃缓慢升温，850、1080和1300℃保温，有利于铝和硅氮化形成足够的氮化铝和氮化硅网络，抑制金属熔体的析出。（2）随着烧成温度的升高，合成材料中β-SiAION相含量降低，15R相含量增加，残余Al2O3减少。

β-SiAlON （ Z = 2.5 ） -15 R （ Z = 3） composites with 50% β-SiAION and 50% 15 R were prepared using Si powder,Al powder and Al2O3 micropowder as starting materials and firing at 1500,1 550,and 1 600 ℃ in nitrogen atmosphere. The influence of firing schedule on synthesis of β-SiAION-15R composites was studied by TG-DSC and XRD. The results show that. （ 1 ） the schedule of slow heating-up at 500-550 ℃ and soaking at 850,1 080,and 1 300 ℃ is favorable for the nitridation of AI and Si to form enough AIN and Si3N4 network, which can prevent the separation of molten metals;（2）the amounts of β-SiAlON phase and residual Al2O3 decline,and the amount of 15R phase rises with the rising temperature.