(1. 天津大學(xué) 材料科學(xué)與工程學(xué)院，天津 300072；
2. 天津大學(xué) 天津市現(xiàn)代連接技術(shù)重點(diǎn)實(shí)驗(yàn)室，天津 300072)
摘 要: 為了緩解涂層和基體之間的熱失配應(yīng)力，采用化學(xué)鍍方法在2A70鋁合金表面上制備Ni-P和Ni-Cu-P過渡層；然后在鍍層表面依次制備CoNiCrAlY粘結(jié)層和ZrO2-8%Y2O3(8YSZ)陶瓷層(質(zhì)量分?jǐn)?shù))，獲得復(fù)合熱障涂層；并采用熱循環(huán)方法評(píng)定該涂層體系的抗熱震性能。結(jié)果表明，采用Ni-P鍍層和Ni-Cu-P鍍層作為過渡層的試樣的熱震壽命分別約為1000次和500次；Ni和Al元素的互擴(kuò)散使過渡層與基體界面區(qū)域形成了擴(kuò)散層和島狀顆粒，一些顆粒與擴(kuò)散層連通后提高了涂層與基體的結(jié)合強(qiáng)度，但孤立的顆粒由于變形能力差，對(duì)涂層的壽命有不利影響；在交變應(yīng)力下顆粒與基體界面處會(huì)形成裂紋，并最終導(dǎo)致涂層剝離。
關(guān)鍵字: 熱障涂層；大氣等離子噴涂；化學(xué)鍍；失效機(jī)制
（1. School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China;
2. Tianjin Key Laboratory of Advanced Joining Technology, Tianjin University, Tianjin 300072, China）
Abstract:To relieve the thermal mismatch stress between coatings and substrate, Ni-P and Ni-Cu-P electroless platings were fabricated onto 2A70 aluminum as interlayers. Subsequently, the specimen with plating was covered by CoNiCrAlY bond coat and ZrO2-8%Y2O3(8YSZ) top coat (mass fraction), then a novel thermal barrier coating (TBC) was produced. The thermal shock resistance of TBCs was evaluated by heat cycle test. The results indicate that the lifetimes of TBC with Ni-P interlayer and Ni-Cu-P interlayer are about 1000 cycles and 500 cycles, respectively. The interdiffusion of Ni and Al results in the formation of diffusion layers and island particles at the interface between interlayers and substrate. The connection between particles and diffusion layers improves the adhesion of coatings with substrate, while isolate particles are harmful to the lifetime of coatings due to their poor deformation ability under alternative stress. Crack initiation happens at the interfaces between particles and substrate, which leads to coatings spallation.
Key words: thermal barrier coating; air plasma spray; electroless plating; failure mechanism
