热处理气氛对ZrO_2活性扩散障/NiCrAl涂层界面反应的影响  

Influences of Heat Treatment Atmosphere on Interface Reaction of ZrO_2 Active Diffusion Barrier and NiCrAl Coating

作　　者：刘林涛[1] 李争显[1,2] 华云峰[2] 杜继红[2] 杨晨曦[1] 宗洋洋 

机构地区：[1]西安建筑科技大学冶金工程学院,西安710016 [2]西北有色金属研究院腐蚀与防护研究所,西安710043 [3]东北大学材料与冶金学院,沈阳110819

出　　处：《中国表面工程》2015年第2期53-58,共6页China Surface Engineering

基　　金：国家重点基础研究发展计划(973计划)(2012CB625102);陕西省科学技术研究发展计划(2013kw12-01)

摘　　要：为研究ZrO2活性扩散障的形成机制,采用电子束物理气相沉积技术(EB-PVD)在DD5镍基高温合金表面分别沉积ZrO2先驱层与NiCrAl涂层,分别在真空条件和大气条件下对试样进行温度为700,800及900℃,时间为5h的高温热处理。分析了试样的截面形貌、扩散反应区厚度以及ZrO2/NiCrAl涂层界面处的元素分布,并研究了热处理气氛对ZrO2/NiCrAl涂层界面反应的影响。结果表明:真空条件更有益于界面反应的进行,并发现经过900℃热处理5h后,ZrO2活性扩散障/NiCrAl涂层界面之间形成了致密的Al2O3阻挡层;而在大气气氛下,NiCrAl涂层中部分Al元素向表面扩散形成氧化膜,从而影响了ZrO2/NiCrAl涂层的界面反应。ZrO2 ceramic film and NiCrA1 coating were respectively deposited on DD5 Ni-based supper alloy by electron beam physical vapor deposition （EB-PVD） to investigate the formation of ZrO2 active diffusion barrier. The specimens were heat treated under 700, 800 and 900℃ for 5 h in both vacuum and atmospheric conditions. By comparing the cross section morphology, the thickness of the diffusion-reaction zones and the element nearby the interface of ZrO2/NiCrAl, the influences of the interface reaction between the ZrO2 active diffusion barrier and the NiCrAl coating under different heat treatment conditions were investigated. The results indicate that the vacuum condition is more conducive to the interfacial reaction, and after 900℃/5 h vacuum-treated, a continued and dense A12 03 diffusion barrier forms on the interface of ZrO2/NiCrAl. However, a portion of Al element in NiCrAl coating is diffused to the surface to form the oxidation scale under heat treatment in the atmos-pheric condition, which would damage the interface reaction between ZrO2 and NiCrAl coatings.

关 键 词：界面反应 元素扩散 NICRAL涂层 扩散障 

分 类 号：TG174.444[金属学及工艺—金属表面处理]