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, email: qjzhai@staff.shu.edu.cn Personal website: http://www.foundrymate.com October 11, 2004

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

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.

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

The end. Thank you!

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

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