Abstract:
The oxidation behavior of body-centered cubic (bcc) structure Cr20Mn17Fe18Ta23W22 refractory high-entropy alloy (RHEA) and the microdefects induced by hydrogen ions before and after oxidation were investigated. The results revealed that compared with oxidizing Cr20Mn17Fe18Ta23W22 at 800 °C (6.7 °C/min) for 4 h (ST3, Ar:O2 = 3:1), the heating procedure of oxidizing Cr20Mn17Fe18Ta23W22 at 300 °C (6 °C/min) for 2 h and then increased to 800 °C (5 °C/min) for 4 h is more conducive to the production of oxides without spalling on the surface, i.e., HT1 (Ar:O2 = 1:1), HT2 (Ar:O2 = 2:1) and HT3 (Ar:O2 = 3:1) samples. The oxidation of Cr20Mn17Fe18Ta23W22 RHEA is mainly controlled by the diffusion of cations instead of affinities with O. Additionally, HT1 and HT3 samples irradiated with a fluence of 3.9 × 1022 cm-2 hydrogen ions (60 eV) were found to have a better hydrogen irradiation resistance than Cr20Mn17Fe18Ta23W22 RHEA. The microdefects in irradiated Cr20Mn17Fe18Ta23W22 mainly existed as hydrogen bubbles, hydrogen-vacancy (H-V) complexes and vacancy/vacancy clusters. The microdefects in irradiated HT3 were mainly vacancies and H-V complexes, while the microdefects in irradiated HT1 mainly existed as vacancies and vacancy clusters, as large amounts of hydrogen were consumed to react with oxides on the HT1 surface. The oxides on the surface of the HT3 sample were more stable than those on HT1 under hydrogen irradiation.
摘要:
研究了体心立方(bcc)结构的Cr20Mn17Fe18Ta23W22耐火高熵合金(RHEA)的氧化行为以及氧化前后氢离子引起的微观缺陷。结果表明,与在800°C(6.7°C/min)下氧化Cr20Mn17Fe18Ta23W224h(ST3,Ar:O2=3:1)相比,将Cr20Mn17Fe18Ta23W22在300°C(6°C/min)下氧化2h,然后升高到800°C(5°C/min)4h的加热程序更有利于氧化物的产生,而不会在表面剥落,即,HT1(Ar:O2=1:1),HT2(Ar:O2=2:1)和HT3(Ar:O2=3:1)样品。Cr20Mn17Fe18Ta23W22RHEA的氧化主要受阳离子扩散控制,而不是与O的亲和力。发现通量为3.9×1022cm-2氢离子(60eV)辐照的HT1和HT3样品比Cr20Mn17Fe18Ta23W22RHEA具有更好的耐氢辐照性能。辐照Cr20Mn17Fe18Ta23W22中的微缺陷主要以氢气气泡形式存在,氢-空位(H-V)复合物和空位/空位簇。辐照的HT3中的微缺陷主要是空位和H-V配合物,而辐照HT1中的微缺陷主要以空位和空位簇的形式存在,因为大量的氢气被消耗以与HT1表面上的氧化物反应。在氢辐照下,HT3样品表面的氧化物比HT1表面的氧化物更稳定。