Abstract

Herein, the effects of Gd₂O₃ on the laser cladding NiCoCrAlYTa coatings in terms of microstructure, phase structures, high temperature oxidation behaviors were investigated. The results showed that the addition of Gd₂O₃ changed the composition of coating phases, promoted homogeneous phase distribution, reduced porosity and improved coating density. During oxidation at 1100 °C for 150 h, the increase in the content of added Gd₂O₃ (at mass fractions of 0, 0.5, 1, 2, 5 and 10%) exhibited an initial inhibitory and then increased effect on the weight-gain rate of the coatings. Overall, 1% Gd₂O₃ addition resulted in the greatest improvement in the oxidation resistance of the coatings, with 49.58% decreases in oxidation kinetic constants, respectively, compared with those of unmodified coatings. However, at a Gd₂O₃ content of 10%, the thermally grown oxide on the coating surface exhibited large flaking areas. The high-temperature oxidation kinetic parameters of the coatings exhibited an inverted parabolic form with increasing Gd₂O₃ content. The higher Gd₂O₃ content led to the formation of excessive oxygen diffusion channels along grain boundaries, which is the reason for the decrease in the anti-oxidant performance of the coating.

中文翻译：

---

Gd2O3添加对NiCoCrAlYTa涂层高温氧化性能的影响

摘要

_{本文研究了Gd 2} O ₃对激光熔覆NiCoCrAlYTa涂层显微组织、相结构、高温氧化行为的影响。结果表明，Gd ₂ O ₃的添加改变了涂层的相组成，促进了相分布均匀，降低了孔隙率，提高了涂层致密性。 1100 ℃氧化150 h过程中，添加Gd ₂ O ₃含量（质量分数为0、0.5、1、2、5和10%）的增加对重量表现出先抑制后增加的作用。 -涂层的增益率。总体而言，添加1%的Gd ₂ O ₃使涂层的抗氧化性得到最大程度的改善，与未改性涂层相比，氧化动力学常数分别降低了49.58%。然而，当Gd ₂ O ₃含量为10％时，涂层表面的热生长氧化物表现出大的剥落区域。随着Gd ₂ O ₃含量的增加，涂层的高温氧化动力学参数呈现倒抛物线形式。较高的Gd ₂ O ₃含量导致沿晶界形成过多的氧扩散通道，这是涂层抗氧化性能下降的原因。