Thürlová Hana, Průša Filip
Department of Metals and Corrosion Engineering, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague, Czech Republic.
Materials (Basel). 2022 Nov 9;15(22):7899. doi: 10.3390/ma15227899.
The equiatomic CoCrFeNiMn alloy prepared by mechanical alloying and spark plasma sintering underwent partial substitution of Mn by Al (5, 10 and 15 at.%) to determine its influence on mechanical properties and thermal stability. It was discovered that the higher the Al content, the higher the volume fraction of the hard phase with primitive cubic (PC) crystallographic lattice, which increases the hardness and strength of the alloys. The most promising mechanical properties have been achieved in the CoCrFeNiMn5Al15 alloy reaching the compressive yield strength (CYS) of 2135 ± 21 MPa and the ultimate compressive strength (UCS) of 2496 ± 21 MPa. All the prepared alloys showed good thermal stability as they maintained or only slightly reduced their initial hardness during the 100 h annealing at 800 °C. Furthermore, the higher the Al content, the higher the resistance against high-temperature oxidation. The oxidic layer changed its composition from Mn-oxides (CoCrFeNiMn15Al15 alloy) to Al-based oxides with exceptional protective properties.
通过机械合金化和放电等离子体烧结制备的等原子CoCrFeNiMn合金用Al（5、10和15原子百分比）部分替代Mn，以确定其对力学性能和热稳定性的影响。发现Al含量越高，具有原始立方（PC）晶格的硬相的体积分数越高，这增加了合金的硬度和强度。在CoCrFeNiMn5Al15合金中获得了最有前景的力学性能，其压缩屈服强度（CYS）达到2135±21MPa，极限抗压强度（UCS）达到2496±21MPa。所有制备的合金都表现出良好的热稳定性，因为它们在800℃下100小时的退火过程中保持或仅略微降低了其初始硬度。此外，Al含量越高，抗高温氧化性能越强。氧化层的成分从Mn氧化物（CoCrFeNiMn15Al15合金）转变为具有优异保护性能的Al基氧化物。
