硅酸盐学报

采用天然高分子凝胶进行陶瓷原位凝固成型具有有机物加入量少、无毒等优点． 本文讨论了一种新的凝胶化工艺用以成型陶瓷坯体，其原理是利用尿素作为氢键阻断剂，阻止热明胶溶液冷却时的凝胶化转变． 待球磨、真空除泡等工艺操作完成后，再加入尿酶使尿素分解，明胶大分子重新获得氢键结合能力，在室温下完成凝胶化转变，形成网络结构，实现原位凝固成型． 该成型方法可获得表面光洁，内部均匀的陶瓷坯体．

In_situ consolidation forming process using natural polymer gels has some major advantages such as less binder addition and non_toxicity. A new kind of gelation process for forming ceramic green body is discussed in the present paper. The forming method is based on this process in which gelatine, urea and urease are used. Urea can prevent occurrence of hydrogen bond between gelatine molecules when the hot gelatine solution cool down. This makes the preparation of well_dispersed suspension possible by ball milling, degassing and so on. When urease is added into the suspension, gelatine molecules attract each other and appear in the three_dimensional network structure through hydrogen bonding due to urea decomposition by urease. Then the slurry containing alumina and gelatine will be consolidated in_situ by the gelation process at room temperature, and the green bodies with homogeneous microstructure and very smooth surface can be obtained