Metal-carbide eutectics with multiprincipal elements make superrefractory alloys

作者：Wei, Qinqin; Xu, Xiandong^*; Shen, Qiang^*; Luo, Guoqiang; Zhang, Jian; Li, Jia; Fang, Qihong; Liu, Chain-Tsuan; Chen, Mingwei^*; Nieh, Tai-Gang^*; Chen, Jianghua^*

来源：Science Advances, 2022, 8(27): eabo2068.

DOI：10.1126/sciadv.abo2068

• HIGH-ENTROPY ALLOYS
• STACKING-FAULT ENERGY
• MECHANICAL-PROPERTIES
• DEFORMATION-BEHAVIOR
• MICROSTRUCTURE EVOLUTION
• PHASE-STABILITY
• PLASTIC-FLOW
• TEMPERATURE
• STRENGTH
• COMPOSITES

Materials with excellent high-temperature strength are now sought for applications in hypersonics, fusion reactors, and aerospace technologies. Conventional alloys and eutectic multiprincipal- element alloys (MPEAs) exhibit insufficient strengths at high temperatures due to low melting points and microstructural instabilities. Here, we report a strategy to achieve exceptional high-temperature microstructural stability and strength by introducing eutectic carbide in a refractory MPEA. The synergistic strengthening effects from the multiprincipal-element mixing and strong dislocation blocking at the interwoven metal-carbide interface make the eutectic MPEA not only have outstanding high-temperature strength (>2 GPa at 1473 K) but also alleviate the room-temperature brittleness through microcrack tip blunting by layered metallic phase. This strategy offers a paradigm for the design of the next-generation high-temperature materials to bypass the low-melting point limitation of eutectic alloys and diffusion-dominated softening in conventional superalloys.

• 单位
  海南大学; 武汉理工大学