摘要
锥体是航空发动机重要热端部件,为保障其高温使用寿命,锥体高温合金基材上会设计很多冷却气孔,同时喷涂耐高温热障涂层。本文重点研究了热障涂层喷涂时锥体冷却气孔的缩孔行为。对五种孔径(0.8 mm~1.6 mm)数百个气膜冷却孔进行了喷涂前后的尺寸测量和统计。结果表明,这些气孔的缩孔率约为12%~23%,随着孔径增大而减小;喷涂余量的长度(约0.09 mm)则与孔径大小无关。通过进一步显微组织分析发现,受喷涂过程中锥体零件自轴旋转(由左向右)的影响,喷涂焰流中颗粒的相对沉积方向并不与基材表面完全垂直,而是形成了斜角度沉积效应(孔左侧沉积更多),这造成了气孔不同方位处的喷涂余量和孔内壁沉积颗粒物存在差异。通过分析,本文提供了冷却气孔处涂层沉积的基本原理,并建议对孔内壁软连接颗粒物进行清理去除。
Hot-end conical assembly is an important section in aero engines.To ensure its service life at high temperatures,abundant cooling holes and hot-resistant thermal barrier coatings(TBCs)are used on the superalloy conical substrate.In this paper,the hole shrinkage behavior due to the spraying of the TBCs was studied.Five different hole sizes(0.8 mm~1.6 mm)were measured before and after the coating spray.The results showed that the shrinkage rate was about 12%~23%decreasing with increasing of the hole size while the oversprayed coating length was hole-size independent(about 0.09 mm).Further microscopic analyses indicated that the overspraying length and powder deposits inside the holes were different at different hole positions,with more oversprayed coating at the left sides of the hole.That was because of an oblique,rather a vertical,deposition effect by the powders in the spray streams against the surface of the conical substrate which was rotating(left to right direction)during the coating spraying processes.The analyses in this paper provided the basic understanding of the coating spray principle at the cooling holes.Considering the possible erosion harm,we suggest that the soft-connecting deposits at the inner surface of the holes should be cleaned.
作者
丁晋
舒琴
钟代银
王平友
黄思谦
Ding Jin;Shu Qin;Zhong Daiyin;Wang Pingyou;Huang Siqian(Aero Engine Corporation of China Guizhou Liyang Aero Engine Co.,Ltd.Guiyang 550014)
出处
《热喷涂技术》
2022年第1期61-67,45,共8页
Thermal Spray Technology
关键词
航空发动机
锥体
冷却气孔
缩孔
Aero engine
Conical assembly
Cooling hole
Hole shrinkage
