四元Gd_55−xZr_xAl₂₃Ni₂₂非晶合金的凝固形成机理和微观力学性能研究

Here, we study the solidification mechanism and micromechanical properties of Gd_55−xZr_xAl₂₃Ni₂₂ (x=0, 15, 25, 35, 45, 55) amorphous alloys in this work. As a result of the immiscibility gap in Zr-Gd, the liquid quaternary Gd-Zr-Al-Ni alloy occurs the metastable phase separation at a high undercooling. Only when Zr and Gd do not coexist, the liquid ternary Gd₅₅Al₂₃Ni₂₂ and Zr₅₅Al₂₃Ni₂₂ alloys can quickly solidify to a single amorphous phase. At an undercooling of 530 K, the liquid Zr₄₅Gd₁₀Al₂₃Ni₂₂ alloy undergoes metastable phase separation in the manner of nucleation and growth. Therefore, it results in the formation of a spherical morphology with dual amorphous phases. The liquid Gd_55−xZr_xAl₂₃Ni₂₂ (x=15, 25, 35) alloys are separated at 189, 336, and 438 K, respectively, and form the reticular structure dual amorphous phases. With the increase of the volume fraction of the amorphous AM-Zr phase, the average hardness of the amorphous alloy increases from 3.95 to 7.95 GPa, and the elastic modulus increases from 58.27 to 101.37 GPa. The wear resistance coefficient of the amorphous alloy increases from 5.2×10¹⁰ to 3.81×10¹¹ Pa, and the apparent friction coefficient decreases from 0.11 to 0.05 with the increase of Zr content.