Materials Development and Mechanical Properties of Single-Phase High Entropy Alloys

单相高熵合金的材料开发和力学性能

• 批准号: 388739063
• 负责人: Dr. Michael Feuerbacher
• 金额: --
• 依托单位: Lehrstuhl Metallische Werkstoffe
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/388739063?language=en
• 关键词: Materials; Development; Mechanical; Properties; Single

The key objective of the project is to investigate single-phase high entropy alloys (HEA) with fcc, bcc and hcp crystal structures with focus on fundamental properties. As a base composition for fcc solid solutions equiatomic CrMnFeCoNi, for bcc equiatomic TiZrNbHfTa and for hcp equiatomic YgdTbDyHo are to be investigated.Entropy measurements will be carried out by determination of the specific heat capacity and subsequent integration over temperature. These measurements will indicate if thermal entropy in connection with configurational entropy have different influences for pure metals in comparison to fcc, bcc and hcp HEA. Of particular interest here is hcp YgdTbDyHo because the lanthanide elements are very similar to each other. The project will investigate whether dislocations consider these atoms identical hence resulting in no net solid solution strengthening or whether a so-called Gibbs paradox also exists for mechanical properties.The critical resolved shear stresses as basic measures of mechanical strength will be determined and compared to each other for all three mentioned HEAs. The impact of further elemental additions to these HEA base alloys onto the CRSS as well as the phenomenon of deformation localization will be addressed.Within the project, the HEA alloy samples will be produced at the University Bayreuth (UBT) and the Forschungszentrum Jülich (FZJ). If possible, samples will be prepared as single crystals by zone melting or Bridgman casting. Mechanical testing will be carried out with proprietary equipment on miniature specimens from cryogenic temperatures up to high temperatures. Elastic properties will be measured as a function of temperature on small (4x5x6 mm^3), single crystal fcc, bcc and hcp HEA samples by ultrasonic resonance spectroscopy.Microstructure analysis and investigation of deformation mechanisms are performed by scanning and transmission electron microscopy.

该项目的主要目的是研究具有fcc、bcc和hcp晶体结构的单相高熵合金（HEA），重点研究其基本性质。研究了催化裂化固溶体的等原子组成CrMnFeCoNi，催化裂化固溶体的等原子组成TiZrNbHfTa和催化裂化固溶体的等原子组成YgdTbDyHo。熵的测量将通过确定比热容和随后对温度的积分来进行。这些测量将表明，与fcc、bcc和hcp HEA相比，与构型熵相关的热熵对纯金属是否有不同的影响。这里特别有趣的是hcp YgdTbDyHo因为镧系元素彼此非常相似。该项目将调查位错是否认为这些原子相同，从而导致没有净固溶体强化，或者所谓的吉布斯悖论是否也存在于机械性能中。作为机械强度的基本测量指标的临界分解剪应力将被确定并相互比较所有上述三种HEAs。进一步的元素添加到这些HEA基合金对CRSS的影响以及变形局部化现象将被解决。在该项目中，HEA合金样品将在拜罗伊特大学（UBT）和德国科学研究中心（FZJ）生产。如果可能，样品将通过区域熔化或布里奇曼铸造制备成单晶。机械测试将使用专有设备在低温到高温的微型样品上进行。弹性性能将通过超声共振光谱法测量小（4x5x6mm ^3），单晶fcc， bcc和hcp HEA样品的温度函数。利用扫描电镜和透射电镜对其进行了显微组织分析和变形机理研究。