EB—PVD梯度热障涂层的制备及其热疲劳性能

DEVELOPMENT OF EB-PVD GRADIENT THERMAL BARRIER COATINGS AND THEIR THERMALIGUE BEHMIORS

采用 ＥＢ—ＰＶＤ的方法，连续蒸发按一定组分比混合的 Ａ１＋Ａｌ２Ｏ３＋ＺｒＯ２混合源，在 Ｎｉ基高温合金基体上制备了一种新型结构的热障涂层，ＳＥＭ和ＥＤＳ的观察、分析表明，这种涂层实现了由金属粘结层向陶瓷顶层的微观结构的梯度过渡和化学成分的连续变化．涂层的基本结构为 ＮｉＣｏＣｒＡｌＹ／ Ｎｉ３Ａｌ／ Ｎｉ３Ａｌ＋Ａｌ２Ｏ３／ Ａｌ２Ｏ３／ Ａｌ２Ｏ３＋ ＺｒＯ２／ ＺｒＯ２这种梯度热障涂层在１０５０℃的抗高温氧化性能优于传统的二层结构的热障涂层经１０５０℃保温３０ ｍｉｎ，迅速冷却至室温的热循环测试３００次后，涂层没有发生剥落。

A new type thermal barrier coating was produced by the continuous evaporation and deposition of the mixture source of A1+Al2O3+ZrO2 with certain fraction ratio onto Ni-based superalloy by means of EB-PVD. The result obtained by SEM with EDS shows that the microstructure of the coating transfers gradually from metallic bond coat to ceramic top-coat and the composition distribution in the coating also changes continuously. The fundamental structure of the coating is NiCoCrAlY/ Ni3Al/ Ni3Al+Al2O3/ Al2O3/ Al2O3+ ZrO2/ ZrO2. The gradient thermal barrier coating has a better resistance to high temperature oxidation at 1050 ℃ than conventional two-layered coating. Subjected to 300 thermal cycling tests performed at 1050 ℃ for 30 min and forced air cooling to room temperature, the coating did not failed and exhibits good resistance to thermal shock.