Thermally stable ultrafine grained copper induced by CrB/CrB2 microparticles with surface nanofeatures via regular casting

• 作者: Gongcheng Yao Chezheng Cao Shuaihang Pan Jie Yuan Igor De Rosa Xiaochun Li
• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2020,（23）
• 页码范围: 55-62
• 页数: 8页
• 语种: 英文

摘要

Ultrafine-grained (UFG)/nanocrystalline materials possess novel properties.Refining as-solidified grains of metals to the ultrafine and even nanometer scale by nanoparticles via slow cooling has been recently discovered.Here,we report that microparticles (CrB and CrB2) with surface nanofeatures can also enable ultrafine/nano grains via slow cooling.CrB/CrB2 microparticles,formed by coalescence of nanoparticles in Cu matrix,display surface nanofeatures,which induce substantial grain refinement and stabilization down to the ultrafine/nano scale.The UFG Cu/CrB and Cu/CrB2 samples exhibit exceptional thermal stability,comparable to UFG Cu induced by nanoparticles,without coarsening after annealing at 600℃ for 1 h.The microhardness,strengths,and Young's moduli of the Cu/CrB and Cu/CrB2 samples are significantly enhanced over pure Cu.This discovery has great potential to advance the mass production UFG/nanocrystalline for widespread applications.