晶粒细化对Cr-25Nb合金高温氧化行为的影响  

Effects of Grain Refinement on High Temperature Oxidation Behavior of Cr-25Nb Alloys

作　　者：郑海忠[1,2] 鲁世强[1] 

机构地区：[1]南昌航空大学,江西南昌330063 [2]南京航空航天大学,江苏南京210016

出　　处：《稀有金属材料与工程》2010年第10期1802-1806,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50474009);航空科学基金(05G56003);博士启动基金(EA200901372);江西省材料工程中心项目(ZX200901002)

摘　　要：采用电弧熔铸和机械合金化+热压烧结技术制备晶粒尺寸相差较大的Cr-25Nb合金,研究其在950及1200℃空气中的氧化行为。结果表明,熔铸态及机械合金化Cr-25Nb合金氧化后均没有发生Cr的单一外氧化,而形成了以Cr2O3为外层、NbCrO4为内层的双层氧化膜结构;机械合金化Cr-25Nb合金在950及1200℃的氧化速度均小于熔铸态合金,特别是在1200℃氧化100h后,熔铸态Cr-25Nb合金的氧化增重是机械合金化合金的2倍多。这主要是因为晶粒细化促进了氧化膜内应力的释放,提高了氧化膜与基体的粘附性。In order to discuss the influence of grain refinement on the oxidation behavior of binary two-phase alloys, Cr-25Nb alloys with different grain sizes were prepared by arc-casting and mechanical alloying, and their oxidation behaviors at 950 and 1200 degrees C in air were investigated. The results show that in both alloys a single and continuous Cr2O3 film did not form, but a complex oxidation films occurred which contained an outer layer of Cr2O3 plus an inner layer of NbCrO4. The oxidation resistance of mechanically alloyed Cr-25Nb was higher than that of the cast alloy. In particular, the mass gain of the cast alloy is twice as much as that of mechanically alloyed alloy when they were oxidized at 1200 degrees C for 100 h. The differences observed above are attributed to that fine grains can accelerate the relaxation of the oxide scale stress and increase the adhesion of the oxide layer on the matrix.

关 键 词：晶粒细化 机械合金化 高温氧化行为 Oxidation Behavior High Temperature 氧化膜结构 熔铸 铸态合金 热压烧结技术 氧化增重 氧化速度 力的释放 晶粒尺寸 合金氧化 粘附性 外氧化 制备 相差 外层 内层 

分 类 号：TG172[金属学及工艺—金属表面处理]