CoNiCrAl涂层及应力对定向凝固镍基高温合金蠕变组织和元素扩散的影响  

Effect of CoNiCrAl coating and stress on creep microstructure and elemental diffusion of directionally solidified nickel-based superalloy

作　　者：刘倩 曹铁山[1] 王威 迟庆新 程从前[1] 赵杰[1] Liu Qian;Cao Tieshan;Wang Wei;Chi Qingxin;Cheng Congqian;Zhao Jie(School of Materials Science and Engineering,Dalian University of Technology,Dalian Liaoning 116024,China;AVIC Shenyang Engine Design Institute,Shenyang Liaoning 110000,China)

机构地区：[1]大连理工大学材料科学与工程学院,辽宁大连116024 [2]中国航发沈阳发动机研究所,辽宁沈阳110000

出　　处：《金属热处理》2024年第3期262-268,共7页Heat Treatment of Metals

基　　金：航空发动机及燃气轮机基础科学中心项目(P2021-A-IV-001-001)。

摘　　要：将附着有/无CoNiCrAl涂层的试样设计为阶梯状,目的是排除其他环境因素的影响,研究950℃高温下应力对DZ411高温合金蠕变组织和元素扩散的影响,同时分析涂层对试样的保护作用。结果表明,涂层可以大幅提高试样的蠕变寿命。发现随着试样所受的应力越大,γ′相退化程度越高,紧密度也越高,特别是高应力区的γ′相完全筏化,其余部位呈现不同程度的球化,有涂层试样在高应力区的涂层被严重破坏,低应力区和无应力区的涂层仅发生轻微氧化;无涂层试样表面氧化程度随应力增大而增大,高应力区则较为严重,出现了裂纹、疏松等缺陷,而应力低的位置表面仍较完整。并且元素扩散随应力也发生变化,在试样表面形成了不同的氧化物,其中有涂层试样Ti元素含量从基体到氧化层表面逐渐降低,且随应力降低呈减小趋势,Cr元素含量由表及里持续上升后降低。By designing the specimens with/without CoNiCrAl coatings as stepped ones to exclude other environmental factors,the effect of stress on the creep microstructure and elemental diffusion of DZ411 superalloy at 950℃was studied,and the protective effect of the coating on the specimen was analyzed.The results show that the coating can significantly increase the creep life of the specimen.It is find that the greater the stress in the specimen,the higher the degree of degradation of theγ′phase and the higher the degree of compactness,especially theγ′phase in the high-stress zone is completely rafted,and that in the rest zones shows different degrees of spheroidization.The coating of the coated specimen in the high-stress zone is seriously damaged,while the coating in the low-stress and the non-stress zones only undergo slight oxidation.The degree of oxidation on the surface of the uncoated specimen increases with the increase of stress,though that in the high stress zone is more serious and with defects such as cracks and looseness,while the surface of the low stress position is still kept more complete.In addition,the element diffusion also changes with the stress,and different oxides are formed on the surface of the specimens,among which the Ti element content of the coated specimen gradually decreases from the matrix to the oxide layer surface,and decreases with the decrease of stress,while the Cr element content continues to increase from the surface to the inside and then decreases.

关 键 词：DZ411高温合金 CoNiCrAl涂层 应力 蠕变 扩散 筏化 

分 类 号：TG146.1[一般工业技术—材料科学与工程]