块状菱镁矿高温烧结动力学  

Sintering Kinetics of Block Magnesite under High Temperature

作　　者：栾旭[1,2] 周宝余[1] 李志坚[1,2] 吴锋[1,2] 曲殿利[1,2] 李林山 

机构地区：[1]辽宁科技大学高温材料与镁资源工程学院,鞍山114051 [2]辽宁省镁资源与镁质材料工程技术研究中心,鞍山114051 [3]辽宁丰华实业有限公司,大石桥115100

出　　处：《人工晶体学报》2015年第6期1707-1712,共6页Journal of Synthetic Crystals

基　　金：国家科技支撑项目(2012BAB06B02)

摘　　要：采用高温电炉对块状菱镁矿进行煅烧,研究了块状菱镁矿烧结末期（1600~1800℃）方镁石晶粒长大和致密化行为。结果表明：在烧结末期,随着温度升高,晶界快速移动,气孔＂汇聚-排除＂的速率和晶界向曲率中心的移动的速率增加,致使颗粒致密化迅速,方镁石晶粒长大明显。温度在1600~1700℃期间,晶界扩散是控制烧结致密化的主导机制,晶粒生长活化能为1.382×103k J·mol-1,晶粒以结晶长大方式为主;温度在1700~1800℃期间,体积扩散是控制烧结致密化的主导机制,晶粒生长活化能为1.164×103k J·mol-1,晶粒以聚晶长大方式为主。随温度的升高,晶粒长大活化能逐渐减小,晶粒长大速率增加。The block magnesite was calcined using high temperature electric furnace. The grains growth and densification behavior of periclase at last sintering stage of block magnesite（ 1600-1800 ℃） were investigated. The results show that with the temperature increasing,the grain boundary moves rapidly,the rate of pore ＂ convergence-exclusion＂ and the moving speed of the grain boundaries to the curvature center increase,which cause particles densification rapidly and periclase grains grow significantly.During 1600-1700 ℃,grain boundary diffusion is the dominant mechanism of controlling densification,the activation energy of grain growth is 1. 382 × 103 k J · mol- 1and crystallization is the main way of grains growth; At the period of 1700-1800 ℃,volume diffusion is the dominant mechanism of controlling densification,the activation energy of grain growth is 1. 164 × 103 k J·mol- 1and glomerocryst grow is the main way of grains growth. Accompanying temperature increases,the activation energy of grain growth decreases,and the rate of grain growth increases.

关 键 词：块状菱镁矿 烧结末期 晶粒长大 致密化 

分 类 号：TQ175[化学工程—硅酸盐工业]