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采用SEM、EPMA、TEM以及显微硬度测试等手段,研究了温度梯度区域熔化(TGZM)对Al-Cu-Mg合金溶质原子浓度分布、第二相析出以及显微硬度的影响。研究表明:TGZM导致晶界两侧基体中的溶质原子浓度存在显著差异,靠近铸锭边部一侧基体的Cu、Mg溶质原子浓度明显高于靠近铸锭心部一侧基体的溶质原子浓度。在485℃的均匀化处理过程中,晶界两侧晶粒靠近边部一侧有大量第二相析出,而靠近心部一侧则很少或者几乎没有第二相析出。该现象致使同一晶界两侧区域的显微硬度值存在明显差别,并且这种差别无法通过长时间的均匀化处理得以完全消除,在微观上加剧了合金不同区域性能的差异。
The influence of temperature gradient zone melting (TGZM) on the concentration distribution of solute atoms, the precipitation of second phase and the microhardness of Al-Cu-Mg alloy was studied by means of SEM, EPMA, TEM and microhardness test. The results show that the concentration of solute atoms in the matrix on both sides of the ingot is significantly different from that of TGZM. The concentration of solute atoms in Cu and Mg near the edge of the ingot is significantly higher than that in the matrix near the ingot. During homogenization at 485 ° C, a large number of second phases precipitate near the edge of the grain boundaries on both sides of the grain boundaries, while few or almost no second phases precipitate near the core. This phenomenon leads to significant differences in the microhardness values of the regions on both sides of the same grain boundary, and the difference can not be completely eliminated by the long time homogenization treatment, which aggravates the difference in performance of the alloys in different regions microscopically.