Microstructure evolution of wrought aluminum alloy extruded rods and the mechanism of liquid phase formation during reheating were investigated. And the relation between the volume fraction of liquid phase and the recrystallization microstructure was proposed. The results show that increase in reheating temperature and time can augment the volume fraction of liquid phase and accelerate the grain spheroidization, as a result of which the requirement of semi-solid forming can be satisfied. Due to the higher aberration energy of grain boundary, the melting point is lowered as a result of the easy diffusion of atoms. At higher reheating temperature the grain boundary melts, the growth of the recrystallized grain is inhibited and the grain is refined. The composition of the low melt-point phase along the recrystallized grains was determined using EDS. It can be seen from the experimental results that when the extrusion rod of the wrought aluminum alloy is reheated at 610℃ for 20min, perfect fine equiaxial grains can be obtained, the average grain size is about 66.34μm and the volume fraction of solid phase is about 68%.
参考文献
| [1] | M C Flemings;R G Piek.[J].Metallurgical and Materials Transactions:1925. |
| [2] | D H Kirkwood;P Kapranos.[J].Metallic Materials:16. |
| [3] | M C Flemings.[J].Metallurgical and Materials Transactions:173. |
| [4] | G M Lu;J Dong;J Z Cui.[J].Acta Metall Sin:1184. |
| [5] | E Tzimas;A Zavaliangos.[J].Materials Science and Engineering:217. |
| [6] | M Kiuchi;S Sugiyama.[J].Materials Shaping Technology:39. |
| [7] | M Nakada;Y Shiohara;M C Flemmings.[J].ISIJ International,1990(01):27. |
| [8] | 董杰,刘晓涛,赵志浩,包卫平,崔建忠.结晶器材料对低频电磁铸造超高强铝合金铸态组织的影响[J].金属学报,2004(02):215-219. |
| [9] | D A Porter;K E Easterling.Phase Transformations in Metals and Alloys[M].北京:冶金工业出版社,1988:325. |
| [10] | W M Mao;X B Zhao.Recrystallization and Grain Growth in Metals[M].北京:冶金工业出版社,1994:271. |
| [11] | D Feng.Physics of Metal[M].北京:科学出版社,1987:146. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%