【摘要】 为满足生物医用领域对高性能合金的迫切需求，采用高速轧制技术制备了纳米晶Zn-3Cu-0.2Sr-xLi(x=0,0.2, 0.4,质量分数，%)合金。在高速轧制过程中产生了大量位错，为再结晶提供了充足的驱动力。添加Li元素能够促进相和β相的形成，这些第二相提供了丰富的异质形核位点和强的钉扎作用，在促进再结晶晶粒形核的同时抑制其长大。Li元素含量为0.4%(质量分数)的合金经高速轧制后，晶粒尺寸从181.8μm减小至50 nm。Li元素含量为0.4%(质量分数)的轧制态合金的极限抗拉强度、屈服强度和伸长率分别为433.3 MPa、389.2 MPa和15.2%，与未添加Li元素的铸态合金相比，屈服强度提高了173%，伸长率提升了591%。纳米晶强化是主要的强化机制，对轧制态Zn-3Cu-0.2Sr-0.4Li合金屈服强度的贡献率高达70.4%。更多还原

【Abstract】 Nanocrystalline Zn-3Cu-0.2Sr-xLi(x=0, 0.2, 0.4, wt.%) alloys were prepared via high-speed rolling to meet the urgent demand for high-performance alloys in the biomedical field. The high-speed rolling process generated numerous dislocations, providing sufficient driving force for recrystallization. The addition of Li promoted the formation of ε and β phases. These secondary phases provided abundant heterogeneous nucleation sites and a strong pinning effect, facilitating recrystallized grain nucleation while inhibiting its growth. The grain size of the alloy containing 0.4 wt.% Li was refined from 181.8 μm to 50 nm after rolling. The ultimate tensile strength, yield strength, and elongation of the rolled alloy containing 0.4 wt.% Li achieved 433.3 MPa, 389.2 MPa, and 15.2%, respectively. Compared to the as-cast Li-free alloy, 0.4 Li alloy demonstrated a 173% increase in yield strength and a 591% improvement in elongation. Nanocrystalline strengthening was the dominant mechanism, contributing 70.4% to the total yield strength of the rolled Zn-3Cu-0.2Sr-0.4Li alloy.更多还原