Abstract The sintering behavior of Cu-9Al alloys prepared from die pressing of elemental powders was investigated. The experimental results and kinetic analysis showed the formation of three consecutive layers of Al2Cu, Al4Cu9, and AlCu phases, with Al2Cu appearing first in the initial solid phase sintering stage. A liquid phase formed in the intermediate stage, resulting from the eutectic reaction between Al and Al2Cu phases at 500 °C, which is 47 °C lower than the equilibrium reaction temperature. Swelling occurred when the liquid phase infiltrated the gaps between the copper particles, leaving pores at the original sites of Al particles and Al2Cu. In the final stage of sintering, the Al-rich phases (Al2Cu and AlCu) transformed to Al-poor phases (Al4Cu9 and α-Cu) in the temperature range of 500–565 °C. Al4Cu9 and α-Cu then transformed to AlCu3 (β) above the eutectoid reaction temperature (565 °C), whereas AlCu3 transformed to α-Cu and eutectoid phases (α-Cu + Al4Cu9) during cooling. The pure copper transformed to AlCu3, and the pore volume decreased at 1000 °C. The microstructure study helps manipulate precisely the sintering process of Cu-Al alloys and optimize the microstructure with a high dimensional accuracy.

中文翻译：

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元素粉制备Cu-9Al合金的烧结机理

摘要 研究了单质粉末模压制备的Cu-9Al合金的烧结行为。实验结果和动力学分析表明，形成了三个连续的 Al2Cu、Al4Cu9 和 AlCu 相层，Al2Cu 在初始固相烧结阶段首先出现。在中间阶段形成液相，这是由于 Al 和 Al2Cu 相在 500 °C 下发生共晶反应，比平衡反应温度低 47 °C。当液相渗入铜颗粒之间的间隙时发生溶胀，在铝颗粒和 Al2Cu 的原始位置留下孔隙。在烧结的最后阶段，在 500-565 °C 的温度范围内，富铝相（Al2Cu 和 AlCu）转变为贫铝相（Al4Cu9 和 α-Cu）。Al4Cu9 和 α-Cu 然后在高于共析反应温度 (565 °C) 时转变为 AlCu3 (β)，而 AlCu3 在冷却过程中转变为 α-Cu 和共析相 (α-Cu + Al4Cu9)。纯铜在 1000 °C 时转变为 AlCu3，孔体积减小。微观结构研究有助于精确控制 Cu-Al 合金的烧结过程，并以高尺寸精度优化微观结构。