燃烧合成长柱状Yb α-Sialon粉体

Combustion Synthesis of Rod-like Yb α-Sialon Powders

研究了各参数对燃烧合成长柱状Ybα-Sialon相组成及形貌的影响。结果表明,不同m,n值对燃烧产物相组成有很大影响。原料中Si3N4,AlN,NH4F的增加有利于Si的氮化,同时,Si3N4和NH4F的增加使α-Sialon晶粒由柱状转变为颗粒状。燃烧合成长柱状α-Sialon的形成过程是α-Sialon首先从Yb-Si-Al-O-N液相中形核析出,然后在适宜的生长条件下择优生长,发育成长柱状晶体。

The effects of various experimental paramete rs on combustion synthesis of single phase Ybá-sialon powders characterized by o ne-dimension elongated morphology have been measured.The results show that rai sing the AlN,Si 3 N 4 and NH 4 F content of the raw mixtures is beneficial for the nitrification of Si,but is unfavourable for the formation of rod-like morphology.The mechanism of pha se formation is thatá-sialon crystals precipitate firstly from liquid Yb-Si-Al-O-N and then develop into the rod-like crystals u nder suitable conditions .