一种适合于AlN陶瓷注射成形的蜡基粘结剂

Study on the wax based polymer binder in injection molding of aluminum nitride

研究开发了一种适合于AlN陶瓷注射成形的蜡基多聚合物粘结剂.通过理论计算分析了所用粘结剂组元的热力学相容性.利用毛细管流变仪测量了喂料的流变性能.结果研究表明,当粉末装载量为61％(体积分数)时,该粘结剂体系和粉末能够均匀顺利地混合,此时喂料的流变因子为0.7～0.76(150℃),呈现典型的假塑性流体特征并具有良好的注射性能;喂料有一定的温敏性,但是对注射压力的变化不敏感,最佳注射温度在150～160℃之间.采用热重分析方法研究了粘结剂的热分解行为,有效地指导了脱脂工艺的设计,并通过考察不同温度下的脱脂形貌,研究了脱脂工艺的合理性.实验表明,该多聚合物粘结剂在脱脂过程中能够起到优良的形状维持作用,对于厚度为8mm的AlN零件来说,脱脂总时间为60h左右.因此,该粘结剂体系是一种性能优异、适合于AlN陶瓷注射成形的粘结剂.

A Wax based polymer binder suitable for CIM of aluminum nitride was studied in the paper. Thethermal miscibility of the binder was researched in theory. The rheological properties of feedstock provethat the AIN powder and binder can be mixed in 61% powder loading freely. The rheological index rang-es form 0.70 to 0.76, which shows that rehological model of the mixture belongs to pseudoplastic whichhas good injection ability. The best injection temperature ranges from 150～160 ℃. The reasonabledebinding cycle is determined on observing the TGA plot of binder by analyzing the microstructure at different debinding tempwrature. The binder has excellent shape retention ability during debinding process.The total debinding time is about 60 h for AlN sample with 8mm thickness.