Production of globular microstructure of A356 aluminium alloy by cooling channel and strain induced melt activation processes: morphological and hardness studies
Production of globular microstructure of A356 aluminium alloy by cooling channel and strain induced melt activation processes: morphological and hardness studies
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DOI：
10.1179/1743133612y.0000000033
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发表时间：
2013-04
影响因子：
1.4
通讯作者：
H. Heshmati;M. Ketabchi;A. Kalaki;M. Tahriri;M. Ashuri
中科院分区：
文献类型：
--
作者：
H. Heshmati;M. Ketabchi;A. Kalaki;M. Tahriri;M. Ashuri
与传统的铸造工艺相比，半固态合金的加工具有许多优点，如减少宏观偏析、气孔和改善机械性能。本文研究了采用冷通道法和应变诱导熔体激活法（SIMA）制备的A356合金，并对其显微组织和硬度进行了评价。首先，在冷却通道工艺中，晶粒尺寸小于常规铸造工艺中的晶粒尺寸，并且随着时间的增加而增加。在热处理前，SIMA试样的显微组织向轧制侧伸长，而在冷却通道工艺中为球形组织。SIMA工艺下试样的硬度值大于未热处理的冷却通道工艺下试样的硬度值。当固溶退火在2 h内进行时，在两个样品中观察到球状组织。最后确定试样的晶粒尺寸为150 μm，硬度为60 HV。
Abstract Processing of alloys in the semisolid state has several advantages over conventional casting processes, such as reduction in macrosegregation, porosity and improved mechanical properties. In this study, produced A356 alloy by means of cooling channel and strain induced melt activation (SIMA) processes has been investigated, and their microstructures and hardness were evaluated. At first, in cooling channel process, the grain size is smaller than that in the conventional cast processes and increases with increasing time. Before heat treatment, the microstructure of the SIMA sample is elongated towards the rolling side in contrast to spherical structure in the cooling channel process. The hardness value of sample in the SIMA process is greater than that in the cooling channel process without heat treatment. When the solution annealing was carried out within 2 h, the globular microstructure in both samples was observed. Finally, the grain size and the hardness of samples were determined as 150 μm and 60 HV respectively.