摘要
利用光学显微镜(OM)、扫描电子显微镜(SEM)、能谱仪(EDS)、X射线光电子能谱(XPS)、电子探针(EPMA)等分析手段,研究了热等静压气氛对铸造高温合金K4169微观组织的影响。结果表明,采用近高纯氩气热等静压的试样(编号B)的氧化层厚度约为26μm,大致分为3层,外层为Cr2O3,TiO2,Al2O3等氧化物,中间层为Cr2O3,内层主要为内氧化物Al2O3,Al2O3呈现规律分布。合金表面氧化引起合金表面层形成Cr2O3和Al2O3等氧化物,导致Al等合金元素贫化。大块状的TiO2会使致密的Cr2O3和Al2O3氧化膜变得疏松,从而加速试样B的内氧化。而采用K4169合金碎屑保护的试样(编号B-1)的氧化层厚度仅为6μm,主要由Cr2O3,TiN和Al2O3组成。在Cr2O3和Al2O3氧化膜表面形成具有较好抗氧化性的TiN,避免形成TiO2,可以抑制试样B-1进一步发生氧化,未发现明显的合金元素贫化。采用合金碎屑掩埋法可防止合金表面氧化,显著减轻合金基体中Al等元素的贫化程度。
The effect of hot isostatic pressing(HIP)atmosphere on microstructure of cast superalloy K4169 was investigated by means of optical microscope(OM),scanning electron microscope(SEM),energy-dispersive spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS),electron probe microanalysis(EPMA).The results showed that the thickness of the oxide layer was about 26μm for the specimen(Specimen B)after hot isostatic pressing via near high purity argon,which was approximately divided into three layers,the outer layer was Cr2 O3,TiO2,Al2 O3 and other oxides,the middle layer was Cr2 O3,and the inner layer was an inner oxide A1203,which presented a regular distribution.The alloy surface oxidation led to the formation of Cr2 O3,A1203 and other oxides in the alloy surface layer,which resulted in the alloy depletion of Al and other alloy elements.The bulk TiO2 made the dense Cr2 O3 and A1203 oxide film looser,thus accelerating the internal oxidation of Specimen B.However,the oxide layer thickness of the specimen protected by K4169 alloy debris(Specimen B-1)was only 6μm,and it was mainly composed of Cr2 O3,TiN and A1203.The formation of TiN with good oxidation resistance on the surface of the Cr203 and A1203 oxide film avoids the formation of TiO2,which could effectively inhabit the further oxidation of the Specimen B-1.Therefore,there was no obvious alloy depletion on the surface.The alloy surface oxidation could be prevented by burying the castings in the alloy debris,and the depletion degree of Al and other elements in the alloy matrix was reduced significantly.
作者
许文勇
张利冲
郑少辉
王佳华
李周
张国庆
Xu Wenyong;Zhang Lichong;Zheng Shaohui;Wang Jiahua;Li Zhou;Zhang Guoqing(Science and Technology on Advanced High Temperature Structural Materials Laboratory,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2020年第4期363-369,共7页
Chinese Journal of Rare Metals
基金
国家重点研发计划项目(2017YFB0305800)资助。
关键词
热等静压
高温合金
合金元素贫化
氧化
hot isostatic pressing
superalloy
alloy depletion
oxidation
