Sc alloying is usually carried out by adding a small amount of Sc in typical aluminum alloys to improve the mechanical properties, however, the effect of high-Sc content on the microstructure and properties of aluminum alloys is rarely concerned. To further understand the role of Sc alloying, several Al–Sc binary alloys with high-Sc content are designed and the relationship between the Sc content and mechanical properties were investigated. It is found that the mechanical properties of Al–Sc binary alloy is determined by both the Sc content and the cooling rate. The addition amount of Sc shows relatively small effect on the mechanical properties at low cooling rate, but higher at high cooling rate, because cooling rate turns the size and distribution of Al₃Sc particles. Through the high Sc content alloy design and melt spinning rapid cooling technology, the densely distributed Al₃Sc precipitate of about 250 nm can be located inside the α-Al grains, resulting in the intracsystalline reinforcement. The combination of high tensile strength (344 MPa) and good plasticity (5.7%) were achieved at a grain size of ~500 nm in the hypereutectic Al–Sc binary alloys ribbons. The significant strengthening could be attributed to multiple strengthening mechanisms including (1) Orowan strengthening; (2) coefficient of thermal expansion (CTE) mismatch strengthening; (3) the Hall-Petch effect caused by grain refinement; (4) solid solution strengthening. When the cooling rate is increased, the effects of thermal mismatch strengthening and Orowan mechanism are more prominent, significantly improving the strength of the Al–Sc alloy. The present experimental results provide an insight into the understanding of microstructural evolution of nanoparticles, and extend the effort for the development of hypereutectic Al–Sc alloys as a member of high-strength structural materials.

Sc合金化通常通过在典型的铝合金中添加少量Sc来提高机械性能而进行，但是，很少关注高Sc含量对铝合金的组织和性能的影响。为了进一步了解Sc合金的作用，设计了几种具有高Sc含量的Al–Sc二元合金，并研究了Sc含量与力学性能之间的关系。结果发现，Al-Sc二元合金的力学性能由Sc含量和冷却速率决定。Sc的添加量在低冷却速率下对机械性能的影响较小，而在高冷却速率下则较高，这是因为冷却速率改变了Al ₃的尺寸和分布Sc粒子。通过高Sc含量的合金设计和熔融纺丝快速冷却技术，使Al ₃密布大约250 nm的Sc沉淀物可以位于α-Al晶粒内部，从而导致胸锁骨内强化。在过共晶Al-Sc二元合金薄带中，在〜500 nm的晶粒尺寸下，实现了高拉伸强度（344 MPa）和良好的可塑性（5.7％）的结合。大量加强可归因于多种加强机制，其中包括（1）加强Orowan；（2）热膨胀系数（CTE）失配强化；（3）晶粒细化引起的霍尔效应。（4）固溶强化。当冷却速率增加时，热失配强化和Orowan机理的作用更加突出，从而显着提高了Al-Sc合金的强度。