(1. 清華大學(xué) 材料科學(xué)與工程系, 北京 100084；
2. 中國科學(xué)院 金屬研究所, 沈陽 110016)
摘 要: 采用5kW連續(xù)CO2激光熱源實現(xiàn)了在銅基材上熔敷熱障涂層, 得到無孔隙、 與基體冶金結(jié)合的密實ZrO2陶瓷層。 發(fā)現(xiàn)在ZrO/NiCoCrAlY界面上生成了Al2O3等氧化物中間層。 NiCoCrAlY結(jié)合層由胞狀晶、 胞狀枝晶及枝晶組成, 其中γ′和β強化相的析出使顯微硬度值顯著提高。 針對TiO2-Al添加劑可以避免裂紋產(chǎn)生, 提出陶瓷涂層高溫化學(xué)反應(yīng)機制和添加劑中鈦在晶界間擴散結(jié)合機制。
關(guān)鍵字: 激光熔敷； 熱障涂層； 化學(xué)反應(yīng)
on copper
LIANG Yong2, SHI Chang-xu2
（1. Department of Materials Science and Engineering,
Tsinghua University, Beijing 100084, China；
2. Institute of Metal Research, Chinese Academy of Sciences,
Shenyang 110016, China）
Abstract:Zirconia thermal barrier coatings were obtained on copper by a 5kW CO2 laser, and dense coatings without porosity and with metallurgical bond to substrates were produced. Al2O3 intermediate layer is found at the interface between NiCoCrAlY layer and ZrO2 ceramic layer. NiCoCrAlY bond coatings are composed of cells, cellular dendrites and dendrites, and the precipitation of γ′ and β phases increases the microhardness values. TiO2-Al dopants can avoid cracks, so the chemical reaction mechanism in ceramic coatings at elevated temperature, and adhesion mechanism by titanium additive diffusion among the grain boundary were proposed.
Key words: laser cladding； thermal barrier coatings； chemical reaction
