摘要
本文研究 SiO_2添加剂对 ZrO_2涂层结构和性能的影响。结果表明,在增加过渡层的同时,添加3wt-%左右的 SiO_2,可使涂层的粘结强度和熱冲击寿命提高4—5倍。添加剂改善涂层寿命的原因是等离子喷涂时,SiO_2熔化渗入 ZrO_2颗粒之间和孔隙中,首先起到液相烧结作用;随后在涂层内汽化(蒸发)增加其孔隙率,使涂层的应力易于松弛,而且,SiO_2以石英相形态沿平行于表面方向塞积在涂层孔隙处,隔绝氧化气氛的进入,起到“自封孔”的作用。在粘结层和 ZrO_2层之间增加过渡层,有利于涂层应力的延缓过渡。
Adding about 3wt-% SiO_2 and inserting graded coating increased adhesivestrength and thermal shock lifetime of plasma sprayed ZrO_2 ceramic coating by four to fivetimes.The improvement of addition on coating and lifetime was attributed to the changes ofcoating structive.First,the molten SiO_2 produced liquid-sintering between ZrO_2 grains andpores of the coating.Secondly,the vaporizing of SiO_2 during spraying increased porosity of thecoating,which contributed to relaxation of stress within the coating.Thirdly,most of SiO_2 ad-dition under the cooling was retained as quartz morphology and piled on pores of the coatingalong the direction parallel to coating surface.Therefore,a＂self-closing pore＂effect wasformed and completely cut off oxidizing atmosphere into the coating.
出处
《材料科学进展》
EI
CAS
CSCD
1992年第2期146-151,共6页
关键词
助剂
钢
喷涂
涂层
性能
氧化锌
plasma sprayed
ZrO_2 coating
SiO_2 addition
structures and properties of the coating
