激光辐射氧化锆-锆英石制品表面的显微结构演变

Microstructure change of ZrO_2- ZrSiO_4 product by laser irradiation

为研究激光与氧化锆制品表面的作用,采用半导体激光器以700 W功率辐照非均态Zr O2-Zr Si O4定径水口试样表面,致其表面局部熔融。借助场发射扫描电镜观察激光辐射前后试样的显微结构变化,利用XRD分析相组成,并用EDS测定化学组成。结果表明:在激光扫描过的区域,烧结氧化锆熔融并重结晶成微米晶体,取向连生成团聚体;而锆英石颗粒全部分解成以树枝晶为特征的m-Zr O2和玻璃相,在局部液相中可见纳米级的m-Zr O2析晶因激剧的mt相变而开裂成微粒。

A ZrO2-ZrSiO4 metering nozzle sample with non-homogeneous microstructure was locally melted by semiconductor laser irradiation with power of 700 W in order to study the effect of laser on the surface of zirconia refractory. The microstructure change of the sample before and after the irradiation was observed by FESEM. The XRD and EDS were used to identify phase composition and chemical composition,respectively. The results show that all zirconia grains are melted and recrystallized into clusters formed of micrometric scale grains in texture growth and zircon particles decompose into m-ZrO2 in form of dendrite crystals and glassy phase completely in the laser irradiated region. The crystals of m-ZrO2 in nanometric scale grains are crystallized from glassy phase in part zone,which crack into micro-particles because of the severe mt phase transformation.