激光烧结Al_(x)CoCrFe_(y)Ni高熵合金的高温氧化行为  

High Temperature Oxidation Behaviour of Al_(x)CoCrFe_(y)Ni High Entropy Alloys

作　　者：李刚[1,2] 孟祥然 李思南 周琳涵 王崇铄 Li Gang;Meng Xiangran;Li Sinan;Zhou Linhan;Wang Chongshuo(College of Mines,Liaoning Technical University,Fuxin 123000,China;Liaoning Provincial Engineering Research Center for High-Value Utilization of Magnesite,Yingkou 115014,China;School of Metallurgy and Materials Engineering,Liaoning Institute of Science and Technology,Benxi 117004,China)

机构地区：[1]辽宁工程技术大学矿业学院,辽宁阜新123000 [2]辽宁省菱镁矿高值利用工程研究中心,辽宁营口115014 [3]辽宁科技学院冶金与材料工程学院,辽宁本溪117004

出　　处：《稀有金属》2025年第1期57-67,共11页Chinese Journal of Rare Metals

基　　金：辽宁省菱镁矿高值利用工程研究中心基金项目(LMNZ2024020103);辽宁省储能与能源利用技术重点实验室基金项目(CNNK202314)资助。

摘　　要：为了探究高熵合金在高温环境中的稳定性和Al,Fe元素对高温抗氧化性能的影响,本文研究了Al_(x)CoCrFe_(y)Ni (x=1.5,2;y=1,1.25,1.5)系高熵合金在900℃的高温氧化行为。采用激光烧结技术制备Al_(x)Co Cr Fe_(y)Ni合金,将合金放置于900℃的流动空气中加热100 h,测试随加热时间,合金的质量变化,建立合金氧化动力学模型。通过X射线衍射(XRD)、扫描电镜(SEM)和能谱(EDS)分析合金氧化层的物相组成和形貌,研究合金的高温氧化机制。结果发现,激光烧结制备的Al_(x)CoCrFe_(y)Ni系高熵合金为体心立方(bcc)相或者bcc+少量面心立方(fcc)双相的固溶体结构。在900℃加热100 h的高温氧化过程中,合金的氧化动力学曲线符合抛物线规律,Al_(2)CoCrFeNi合金的氧化增重曲线抛物线速率常数K_(T)=0.5345,其值最小,具有较好的抗氧化性能。合金的氧化层物相相近,均由细小密集堆叠的Cr_(2)O_(3)相、致密的富Al尖晶石相、不含Al元素片层状堆叠的富Fe尖晶石相和珊瑚状的富Co尖晶石相组成。与带有孔隙不含Al的尖晶石相相比,Al,Cr元素的氧化物连续且致密,对合金基体保护性更好。高熵合金中Al元素含量增加,合金的高温抗氧化性能增强;Fe元素含量增加,合金高温抗氧化性能减弱。激光烧结制备的Al_(x)CoCrFe_(y)Ni系高熵合金的孔隙率高于铸态合金,孔隙加速了合金的高温氧化行为。高熵合金的高温抗氧化性能与组成元素的氧化激活能有关,通过成分优化和工艺控制能够改善高熵合金的高温稳定性,拓展合金的应用范围。The high entropy alloys constituted a novel class of multi-major element alloy materials,typically comprising five or more elements with comparable molar content of each constituent.Owing to the high entropy effect,the crystal structure of these alloys typically manifested as a structurally simple solid solution.AlCoCrFeNi high entropy alloys represented a new breed of high-temperature structural materials,distinguished by their remarkable attributes such as high strength,robust phase stability at elevated temperatures,and resistance to softening under high-temperature conditions.The large-scale production of high-entropy alloys continued to be influenced by various factors,including the price of raw materials and energy consumption during processing.Additionally,the degree of densification of the oxide film formed after oxidation of the alloy at elevated temperatures,the temperature of oxidation,and the properties of alloys prepared through different processes were all interconnected with the oxidation process.Consequently,the high-temperature oxidation resistance of high-entropy alloys was closely linked to the elemental composition,temperature conditions,and manufacturing techniques employed.An investigation into the high-temperature oxidation behavior of these alloys at 900℃ was undertaken to elucidate their stability in extreme thermal environments and to discern the influence of Al and Fe elements on their high-temperature antioxidation properties.The metal powders underwent homogeneous mixing in an F-P4000E high-speed ball mill under an atmosphere of high-purity argon gas,operating at a speed of 300 r·min^(-1) for 4 h.Subsequently,the well-mixed powders were subjected to a pressure of 100 MPa using a PP-60S powder tablet press,yielding pellets with a diameter of 15 mm.Al_(x)CoCrFe_(y)Ni high entropy alloys were then sintered employing a DL-HL-T5000B helium-free cross-flow CO_(2) laser with a laser output power of 1 kW,irradiated for a duration of 10 s.Subsequently,the alloys were subjected to a heating

关 键 词：高熵合金 激光烧结 高温氧化 氧化层 尖晶石相 

分 类 号：TG133[一般工业技术—材料科学与工程]