Rheology and microstructural development of a Al-4wt%Cu alloy in the semi-solid state
Rheology and microstructural development of a Al-4wt%Cu alloy in the semi-solid state
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DOI：
10.1016/s0921-5093(99)00226-9
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发表时间：
1999-11-01
期刊：
影响因子：
6.4
通讯作者：
de Freitas, E
中科院分区：
文献类型：
--
作者：
Ferrante, M;de Freitas, E
采用压痕试验和简单压缩试验两种不同的实验技术，对半固态Al-4wt%Cu合金进行了流变学和微观组织研究。结果表明，再结晶组织比枝晶组织具有更低的粘度，其神学行为可以用幂律描述。用固体体积分数和变形速率分析了Al-4wt%Cu合金的粘度值，从而确定了Al-4wt%Cu合金的假塑性。对于半固态温度范围内的固体粒径和形状演变，实验生长动力学服从经典的D-3 = K(c)t关系，属于Ostwald成熟型生长，但粒径分布比LSW理论预测的要宽。实验和理论生长速率常数的比较表明，固体颗粒的硬撞击导致的粗化是主要的生长机制。(C) 1999 Elsevier Science S.A.版权所有
Rheological and microstructural studies were performed on a Al-4wt%Cu alloy in the semi-solid state employing two different experimental techniques: the indentation test and the simple compression test. Results showed that recrystallized microstructures exhibit lower viscosities than dendritic microstructures and that the theological behavior can be described by the Power Law. The viscosity values were analyzed in terms of solid volume fraction and deformation rate and the pseudoplasticity of the Al-4wt%Cu alloy was thus ascertained. As for the solid particle size and shape evolution within the semi-solid temperature range, the experimental growth kinetics obeyed the classic D-3 = K(c)t relation, which indicates a Ostwald Ripening type of growth, but the particles size distribution was wider than the one predicted by the LSW theory. Also, comparison of the experimental and the theoretical growth rate constants suggested that coarsening due to hard impingement of the solid particles was the main growth mechanism. (C) 1999 Elsevier Science S.A. All rights reserved.