采用热压注法制备多孔氧化铝基陶瓷型芯,研究了Al_2O_3粉粉末粒度分布、Al粉加入量和保温时间对陶瓷型芯性能的影响.研究结果表明:Al_2O_3粉粉末粒度分布显著影响陶瓷型芯的性能,当加入的Al_2O_3粉粉末粒径分别为80,58和45μm,且三种Al_2O_3粉粉末的质量比为1∶1∶1时,制备的陶瓷型芯性能较好;当Al粉加入量(质量分数)为10%时,型芯的综合性能最好,其线性收缩率为-0.85%,抗弯强度为30.43 MPa,气孔率为46.99%,且保温时间对样品的性能影响很小,在1 500℃下保温5h,样品性能稳定,该型芯有望满足陶瓷型芯的铸造要求.
The porous alumina-based ceramic core was built by hot-pressing process. The influences of alumina grain distribution, aluminium content and sintering time on the properties of ceramic cores were studied. The results indicate that alumina grain distribution has significant effects on the proper- ties and compared to other distributions, and ceramic cores made of equal amount of diameters of 80, 58 and 45μm possesses better comprehensive performance. Ceramic cores shows increasingly high ap- parent porosity with the increasing amount of aluminium and ceramic cores with 10% aluminium con- tent have linear shrinkage of --0. 85%, bending strength of 30. 43 MPa and apparent porosity of 46.99%, there is no obvious influence of sintering time on the properties of cores. After sintered at 1 500 ℃ for 5 h, ceramic cores still have stable properties, which can meet the demands of ceramic cores in casting area.