用内凝胶法制备球形Y2O3-ZrO2等离子喷涂粉料

以无机物为前驱物，用内凝胶法制备了适合于等离子喷涂的、粒径在10～50μm范围内的、用氧化钇稳定的氧化锆（YSZ）球形粉末，实验结果表明，通过改变乳化条件可以控制这种粉末的形貌、粒径和粒度分布．利用SEM和光学显微镜观察发现，用该方法得到的粉末主要是球形的，并且符合粒径分布的要求（5～50μm）．致密的球形粉末显示出良好的流动性．差热分析表明，用47mol％氧化钇稳定的氧化锆（YSZ）粉末在468℃有一放热峰，是YSZ粉末的相转变温度．XRD分析表明，上述粉末在800℃条件下煅烧可以得到100％非平衡四方相（t’）的YSZ粉末，没有单斜相存在．

Synthesis of Yttria-Stabilized Zirconia Powders for Plasma Spray by Internal Gelation

Chemical uniform, high-purity spray-grade zirconia powders doped with variable ratios of yttria for ceramic thermal barrier coatings were prepared by an internal gelation process. Both the morphology and particle size of the powders can be controlled by varying the emulsification conditions. Scanning electron microscopic and optical microscopic observations revealed the materials thus obtained to have a predominantly spherical morphology and the requisite size distribution (5～50μm). The dense, calcined micro-spheres showed good flowability. Differential Thermal Analysis (DTA) of 4.7mol% Y₂O₃-ZrO₂ powders (dried at 80℃) indicated that m→’ transformation was happened at 468℃. X-ray diffraction results showed that the crystalline phase of such powders after calcination at 800℃ was 100% nontransformable tetragonal.