CaO-SiO_2-P_2O_5-H_2O系统中CBC材料的溶胶凝胶过程研究 Ⅱ凝胶的烧成过程

STUDIES OF THE SOL-GEL PROCESS OF CHEMICALLY-BONDED CERAMICS DEVELOPED IN THE CaO-SiO 2-P 2O 5-H 2O SYSTEM Ⅱ SINTERING PROCESS OF THE GEL

利用ＸＲＤ，ＩＲ，ＳＥＭ及２９Ｓｉ，３１ＰＮＭＲ等测试技术研究了ＣａＯＳｉＯ２Ｐ２Ｏ５Ｈ２Ｏ系统中干凝胶在烧成过程中的物相变化及物相间发生的化学反应。认为凝胶在烧成过程的不同阶段发生的主要化学反应如下：（１）６７３～７７３Ｋ：由Ｃａ２Ｐ２Ｏ７和Ｃａ（ＮＯ３）２·４Ｈ２Ｏ反应生成了ＯＨＡｐ；（２）７７３～８７３Ｋ：由Ｃａ２Ｐ２Ｏ７和ＣａＯ反应生成了βＣ３Ｐ；（３）８７３～９７３Ｋ：由ＣａＯ和ＳｉＯ２反应生成βＣ２Ｓ。因此粉末材料的主要晶相有：ＯＨＡｐ，βＣ３Ｐ和βＣ２Ｓ，其中Ｓｉ和Ｐ之间有相互固溶现象。

The main reactions taking place in the gel sintering process were studied by XRD,IR,SEM and 29 Si, 31 PNMR.It is revealed that the main chemical reactions at different stages are as follows:(1)in the range of 673～773K,OHAp is synthesized by the reaction between Ca 2P 2O 7 and Ca(NO 3) 2·4H 2O;(2)in the range of 773～873K,the reaction between Ca 2P 2O 7 and CaO takes place to form β C 3P;(3)in the range of 873～973K, β C 2S is synthesized by the reaction between CaO and SiO 2;thus the main crystalline phases of the powder materials are:OHAp, β C 3P and β C 2S,in which Si and P form solid solution with each other.