Abstract：Al-0.2Zr-(0-0.2)Hf alloys were prepared by casting and thermomechanical processing in this study. Optical microscope, scanning electron microscope, and transmission electron microscope were employed to investigate the effects of the combined addition of Zr and Hf on the microstructure, aging behavior, electrical conductivity, and mechanical properties of the Al-Zr-Hf alloys. The results show that primary Al3(Zr,Hf) precipitates are formed during solidification of Al-0.2Zr-0.2Hf alloy. These phases act as heterogeneous nucleation sites and significantly refine the as-cast grains, reducing the average grain size by 60 μm compared with the Al-0.2Zr alloy. After peak aging at 400 ℃/100 h, a large number of finely dispersed Al3(Zr,Hf) phases (with an average diameter of 28 nm) precipitate in the Al-0.2Zr-0.2Hf alloy. These precipitates possess an L12 structure and are fully coherent with the α-Al matrix. They enhance the strength of the alloy via precipitation strengthening, while simultaneously reducing electron scattering by depleting Zr and Hf solute atoms from the Al matrix. After aging at 400 ℃/300 h, the alloy achieves an optimal comprehensive performance, with a tensile strength of 103 MPa, an elongation of 21%, and an electrical conductivity of 33.3 MS/m.
孙珂, 韦启荣, 阳书超, 王斌. Hf微合金化对Al-0.2Zr合金微观组织与力学性能的影响[J]. 粉末冶金材料科学与工程, 2026, 31(4): 364-376.
SUN Ke, WEI Qirong, YANG Shuchao, WANG Bin. Effects of Hf microalloying on the microstructure and mechanical properties of Al-0.2Zr alloys[J]. Materials Science and Engineering of Powder Metallurgy, 2026, 31(4): 364-376.
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