Effect of cooling rate on the microstructure of ZA48 alloy
Jiefang Wang , Shuqing Yan , Jingpei Xie , Zhongxia Liu , Jiwen Li , Wenyan Wang
Journal of Wuhan University of Technology Materials Science Edition ›› 2010, Vol. 25 ›› Issue (5) : 811 -813.
Effect of cooling rate on the microstructure of ZA48 alloy
The effect of cooling rate on the microstructure of ZA48 alloy was investigated. The alloy was prepared using a relatively simple technique, i e, rapid cooling of the melt in a steel wedge mould. The dependence of microstructure on the cooling rate (about 40 to 103 K/s) was determined by the secondary dendrite arm space size measurement, optical microscopy(OM), and transmission electron microscopy (TEM). It is found that the matrix structure over a large cooling rate is composed of α-Al dendrite and eutectoid (α+η), the size of α-Al dendrite decreases with increasing cooling rate. The relationship between the cooling rate and the secondary dendrite arm space size has been established. TEM shows that a large number of small and dispersed precipitations can be seen in the primary α phase of tip region. Electron diffraction pattern shows that the precipitate phase is Zn3Mg2 phase.
cooling rate / microstructure / secondary dendrite arm space size / precipitation
| [1] |
|
| [2] |
|
| [3] |
|
| [4] |
|
| [5] |
|
| [6] |
|
| [7] |
|
| [8] |
|
| [9] |
|
| [10] |
|
/
| 〈 |
|
〉 |