混合稀土Nd_(2)O_(3)和CeO_(2)对氧化镁陶瓷硬度及抗热震性能的影响

Effect of Mixed Rare Earth Nd_(2)O_(3) and CeO_(2) on Magnesia Ceramics' Hardnessand Thermal Shock Resistance

采用轻质微米级(0.5μm)MgO粉末为原料,Nd_(2)O_(3)、CeO_(2)为添加剂,聚乙烯醇为黏结剂,以242 MPa压强干压成型,常压1 550℃下烧结并保温2 h制得MgO陶瓷,对所得试样进行硬度、抗热震性能、显微结构及物相的测定。先探究不同添加量的单一稀土对MgO陶瓷的硬度及抗热震性能的影响,得到Nd_(2)O_(3)和CeO_(2)的最佳添加量ω分别为3%、8%。然后探究混合稀土Nd_(2)O_(3)和CeO_(2)对MgO陶瓷的性能影响,结果表明混合稀土添加总量ω为3%,Nd_(2)O_(3)与CeO_(2)的质量比为3∶7时,氧化镁陶瓷具有最好性能,硬度值为68 HRA,抗热震次数高达19次。

With light magnesium oxide(0.5μm)powder as raw material,rare earth neodymium oxide and cerium oxide as additives,and polyvinyl alcohol as binder,a type of magnesia ceramics was created by sintering at 1550℃for 2 h and pressing molding under atmospheric pressure of 242 MPa.Then,the hardness,thermal shock resistance,micro structure and phase of the samples were investigated.Firstly,the influence of single rare earth with different additive contents on the magnesia ceramics'hardness and thermal shock resistance was investigated,and the optimal addition amount of neodymium oxide and cerium oxide was 3%and 8%,respectively.Then,the effects of mixed rare earth neodymium oxide and cerium oxide on the properties of magnesia ceramics were also studied.The results showed that when the content of mixed rare earth was 3%and the mass ratio of Nd_(2)O_(3)to CeO_(2)was 3∶7,the magnesia ceramics manifested the best performance,the hardness was 68 HRA,and the thermal shock resistance was up to 19 times.