1. Effect of Pulsed Magnetic Field on Solidification Structures of Metals
Metal Solidification Research Group, Shanghai University
Effect of Pulsed Magnetic Field on Solidification Structures of Metals
Zhai Qi-Jie *, Gao Yu-Lai, Li Qiu-Shu
*Corresponding author,
Personal website:
October 11, 2004

2. Four Parts: Background Experimental procedure Results and discussion
Metal Solidification Research Group, Shanghai University
Four Parts:
Background
Experimental procedure
Results and discussion
Conclusions

3. Background: Can obviously refine the solidification structure
Metal Solidification Research Group, Shanghai University
Background:
Can obviously refine the solidification structure
No research on pure metal, e.g. Al
No consensus is acquired about the effect of
magnetic field
Little information is available about the
refinement mechanism

4. Experimental procedure:
Metal Solidification Research Group, Shanghai University
Experimental procedure:
High-voltage pulsed power source
and the solidification equipment
Materials choose: pure Al, gray iron and
stainless steel
Analysis methods: OM, TA

5. Results and Discussions ——Effect on Al
Metal Solidification Research Group, Shanghai University
Results and Discussions ——Effect on Al
(a)
(b)
(c)
(d)
10mm
B=0T
(b) B=0.3T
(c) B=0.38T
(d) B=0.51T
Macrostructure of the solidified samples under the pulsed magnetic field with different intensities

6. Results and Discussions ——Effect on Al
Metal Solidification Research Group, Shanghai University
Results and Discussions ——Effect on Al
Relation between the intensity of the pulsed magnetic field and the average grain size

7. Results and Discussions ——Effect on Al
Metal Solidification Research Group, Shanghai University
Results and Discussions ——Effect on Al
Distribution of the magnetic induction intensity in the intense magnetic generator

8. Results and Discussions ——Effect on Al
Metal Solidification Research Group, Shanghai University
Results and Discussions ——Effect on Al
Relationship between the intensity of pulsed magnetic field and solidification temperature

9. Results and Discussions ——Effect on gray iron
Metal Solidification Research Group, Shanghai University
Results and Discussions ——Effect on gray iron
Chemical composition of experimental gray iron

10. Results and Discussions ——Effect on gray iron
Metal Solidification Research Group, Shanghai University
Results and Discussions ——Effect on gray iron
(a) B=0T
(b) B=1.2T
(c) B=3.1T
(d) B=6.4T
(c)
(b)
(a)
75 μm
(d)
Graphite morphology of hypoeutectic gray iron under different pulsed magnetic field parameters

11. Results and Discussions ——Effect on gray iron
Metal Solidification Research Group, Shanghai University
Results and Discussions ——Effect on gray iron
(a) B=0T
(b) B=0.3T
(c) B=1.2T
(d) B=2.6T
(a)
(c)
(d)
(b)
75 μm
Graphite morphology of hypereutectic gray iron under different pulsed magnetic field parameters

12. Results and Discussions ——Effect on gray iron
Metal Solidification Research Group, Shanghai University
Results and Discussions ——Effect on gray iron
Effect of the magnetic intensity on the
length of the graphite
Effect of the magnetic intensity on the thickness of the graphite

13. Results and Discussions ——Effect on gray iron
Metal Solidification Research Group, Shanghai University
Results and Discussions ——Effect on gray iron
B=0T
B=3.1T
Relation between the temperature and time for solidification of gray iron

14. Results and Discussions ——Effect on stainless steel
Metal Solidification Research Group, Shanghai University
Results and Discussions ——Effect on stainless steel
(h)
(g)
(f)
(e)
(a)
(b)
(c)
(d)
10mm
(a)B=0T
(b)B=0.78T
(c)B=1.10T
(d) B=1.35T
(e)B=1.8T
(f)B=3.00T
(g) B=3.24T
(h) B=3.84T

15. Metal Solidification Research Group, Shanghai University
Conclusions:
The solidified structure of pure aluminum evolved from columnar grains to equi-axed ones, and the grain size becomes smaller as the augment of the intensity of pulsed magnetic field. The effect of the pulsed magnetic field on the solidification temperature of Al can be neglected.
The pulsed magnetic field can refine and improve the graphite morphology of the gray iron. Also, the pulsed magnetic field can decrease its undercooling of the eutectic transformation.

16. Metal Solidification Research Group, Shanghai University
Conclusions:
The solidification structures of austenitic stainless steel are changed from coarse columnar crystals to narrow and thin ones after adding pulsed magnetic field. However, equi-axed grains can’t be obtained.

17. Acknowledgement: Financially supported by
Metal Solidification Research Group, Shanghai University
Acknowledgement:
Financially supported by
(1) National Natural Science Foundation of China, (2) Science and Technology Committee of Shanghai
Municipality

18. The end. Thank you!

19. Experimental equipments:
Metal Solidification Research Group, Shanghai University
Experimental equipments:

20. Schematic of the solidification equipment:
Metal Solidification Research Group, Shanghai University
Schematic of the solidification equipment: 7 10 1 3 4 2 6 5 8 9
1－Magnetic field generator 2− Pouring cup
3−Liquid metal
4−Mould
5−Cooling System 6−Computer-controlled
thermometric system
7−Pad
8−Mobile platform
9－Thermal couples
10－Pulse power source