脉冲电子束作用下热障涂层界面组织结构调控及高温性能增强机制

Thermal barrier coating (TBC) is one of the key techniques in developing advanced heavy-duty gas turbine, and interfacial failure induced by thermally grown oxide (TGO) is the major issue affecting the durability of TBC. In order to improve the high temperature performance of TBC, the proposed project is presenting a new route to modify MCrAlY bond coat, prepared by arc ion plating (AIP), through a high current pulsed electron beam (HCPEB) irradiation. By adjusting the processing parameters of HCPEB, the bond coat surface can be polished and purified, and the microstructures and the state of stress can also be modified. Furthermore, the micro-modulation of the growth and evolution of TGO can be materialized. On this basis, a yttria stabilized zirconia (YSZ) ceramic coating can be deposited onto the irradiated MCrAlY coating surface by electron beam physical vapor deposition (EB-PVD) technique. In order to establish principles for manipulating and manufacturing TBC with high durability, some fundamental ideas are presented in this proposal. The first is to investigate the effects of the modified MCrAlY microstructures on the copying growth behavior of YSZ ceramic coating, interfacial adhesion and thermal cycling performance of TBC. The second is to clearify the relationship between the microstructures and properties of TBC under the effect of HCPEB irradiation. The third is to reveal the growth behavior of TGO and the strengthening mechanisms of TBC under the control of microstructures. The last is to systemize the correlations among the processing parameters, materials microstructures and mechanical performance. The above proposed content involves many innovative scientific issues, and the prospected research achievements will build up a sturdy scientific/technical foundation for enriching and developing the TBC techniques in the future.

热障涂层是发展先进重型燃气轮机的关键热防护技术，由热生长氧化物诱发的界面破坏是影响热障涂层耐久性的关键因素。本项目以改善热障涂层高温性能为主要研究目标，利用脉冲电子束技术辐照电弧离子镀MCrAlY粘结层，通过调整辐照工艺参数对粘结层表面进行抛光与净化处理，并在微观层面上有目的地调控粘结层组织结构及应力状态，以实现对热生长氧化物生长行为的微观控制；在此基础上，利用电子束物理气相沉积技术在改性MCrAlY表面沉积YSZ陶瓷层，通过研究改性粘结层组织结构演变对陶瓷层仿形生长行为、热障涂层界面结合及热循环寿命的影响规律，建立脉冲电子束作用下热障涂层结构与特性的关系，揭示基于微观结构控制的热生长氧化物生长行为及热障涂层延寿机理，形成工艺-材料-结构-性能一体化制造基础理论，实现高寿命热障涂层的控制及制备。相关研究内容涉及众多全新科学问题，其研究成果可以为丰富和发展热障涂层技术提供科学依据和技术基础。

热障涂层是发展先进重型燃气轮机的关键热防护技术，由热生长氧化物诱发的界面破坏是影响热障涂层耐久性的关键因素。本项目以改善热障涂层高温性能为主要研究目标，利用脉冲电子束技术对热障涂层界面结构进行精细调控，通过控制粘结层微观组织结构，实现气相沉积陶瓷层仿形生长及界面强化。在此基础上，通过控制热障涂层界面氧化物层的动态生长行为，实现粘结层抗高温氧化性能增强及热障涂层延寿的目的。该项目揭示了脉冲电子束作用下粘结层组织组分调控机理、气相沉积陶瓷层仿形生长机理、界面氧化物层动态生长机理、以及热障涂层热循环延寿机理，通过多种粘结层材料的结构调控及试验研究，最终确定脉冲电子束技术是提高热障涂层高温性能十分有效的手段。本项目共发表SCI论文10篇、EI及核心论文各1篇；受理国家发明专利3件，其中已授权1件；研究生顺利毕业4人，其中1人获得研究生国家奖学金。本项目顺利完成既定研究目标。