氧化钇对氧化镁陶瓷烧结和抗热震性能的影响

Effects of yttrium oxide on sintering and thermal shock resistance of magnesia ceramics

为提高氧化镁陶瓷抗热震性和烧结性能,以高纯纳米氧化镁为主要原料,高纯纳米氧化钇粉为添加剂,聚乙烯醇为结合剂,制备了氧化镁陶瓷试样,研究了氧化钇添加量(外加,质量分数分别为0、1%、2%、3%和4%)和煅烧温度(1 350、1 450和1 550℃)对氧化镁陶瓷性能的影响。结果表明:氧化钇与方镁石形成有限置换型固溶体,提高了烧结试样致密度;氧化钇抑制了烧结试样中方镁石晶粒生长;氧化钇通过第二相增韧和微裂纹增韧提高了氧化镁陶瓷的抗热震性。

Magnesia ceramic specimens were prepared with high-purity nano-sized magnesia as the main raw material,high-purity nano-sized yttrium oxide as the additive,polyvinyl alcohol as the binder in order to improve the sintering property and thermal shock resistance of magnesia ceramics.The effects of the yttrium oxide addition(0,1%,2%,3%and 4%,by mass,extra-adding)and the calcining temperature(1 350,1 450 and 1 550℃)on the properties of magnesia ceramics were investigated.The results show that the yttrium oxide forms finite substitutional solid solution with periclase,which improves the density of the sintered specimens;yttrium oxide inhibits the periclase grain growth of specimens;the thermal shock resistance of magnesia ceramics is improved by second phase toughening mechanism and microcrack toughening mechanism.