摘要
为了研制一种新型连铸结晶器材料,采用高效能超音速等离子喷涂技术在纯铜基体上制备了Cr2O3陶瓷涂层。使用X射线衍射、扫描电子显微镜、图形软件、彩色3D激光显微镜和显微硬度计对涂层进行了表征及分析,分别在450℃和600℃对涂层进行了热震试验。结果表明,涂层继承了起始粉末的物相,但是Cr2O3的结晶度有所差异;陶瓷涂层表面为良好熔化区和部分熔融颗粒组成的双态组织,涂层断口形貌为典型的片层状组织,涂层截面可见均匀分布的富铬带。涂层孔隙率为1.2%,表面粗糙度为4.763μm,Vickers显微硬度为1 628 MPa。试样在450℃和600℃分别经历了均值为127.4和58.6次热震循环后,其半球顶端出现大面积剥落,但圆柱主体部分完好,表明Cr2O3陶瓷涂层具备良好的抗热疲劳性能,超音速等离子喷涂适合于结晶器铜板表面涂层的制备。
Cr2O3 based （Cr2O3-Ni-5%Al） coatings as an alternative for mold materials were deposited onto a pure copper substrate via a supersonic atmosphere plasma spray （SAPS）. The coatings were examined by X-ray diffraction, scanning electron microscopy, image software, color 3D laser scanning microscopy and micro-hardness tester, respectively. The thermal shock test was conducted at 450 ℃ and 600 ℃, respectively. There was a slight difference between the crystalline degrees of Cr2O3 without the phase transfor- mation at various temperatures. The as-sprayed coating displayed a bimodal surface microstructure, which composed of well melted regions and partially melted particles. Furthermore, a typical porous lamellar structure was observed in the fracture surface, and the chromium-rich regions were uniformly dispersed in the cross-section of the as-sprayed coating. The Cr2O3 coating possessed the sur- face roughness value （Ra） of 4.763 μm, porosity of 1.2% and micro-hardness of 1 628 MPa. The hemispherical dome of samples spalled with the greater surface area after 127.4 and 58.6 average thermal shock cycles but the main part of cylindrical samples was intact, so the coating exhibited the superior thermal shock resistance. The results show that this supersonic atmosphere plasma spray method is suitable for the preparation of the extreme temperature variations coating for casting mould.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2012年第9期1356-1362,共7页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金项目(51002114)
陕西教育厅基金项目(2010JK654)
西安建筑科技大学课题(RC0912)资助项目
关键词
三氧化二铬涂层
超音速等离子喷涂
显微组织
抗热震性能
chromium oxide coating
supersonic atmosphere plasma spray
microstructure
thermal shock resistance
