High strength and high electrical conductivity are needed for the usage of aluminum wire in high-voltage lines. Strength and electrical conductivity are contradictory in metallic materials. Improving strength comes with the sacrifice of electrical conductivity. Here we produced a dual gradient microstructure to improve the strength of aluminum wire without compromising electrical conductivity. Aluminum wires with gradient microstructures and dual gradient microstructures were processed through clockwise torsion and subsequent anti-clockwise torsion. Compared with the gradient microstructural aluminum, aluminum with dual gradient microstructures possesses higher strength and higher electrical conductivity. Microstructural characterizations and numerical simulations further reveals that dual gradient grain size provides extra strain hardening and less electrical resistivity. This explains the high strength and high electrical conductivity in aluminum wire with dual gradient microstructure.

在高压线路中使用铝线需要高强度和高导电率。强度和导电率在金属材料中是矛盾的。强度的提高伴随着电导率的牺牲。在这里，我们生产了双重梯度微结构，以提高铝线的强度而又不影响导电性。通过顺时针扭转和随后的逆时针扭转对具有梯度微结构和双重梯度微结构的铝线进行加工。与梯度微结构铝相比，具有双梯度微结构的铝具有更高的强度和更高的导电性。微观结构表征和数值模拟进一步揭示了双梯度晶粒尺寸可提供额外的应变硬化和较小的电阻率。这解释了具有双重梯度微观结构的铝线的高强度和高电导率。