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Vol.45, No.4, 236 ~ 243, 2007
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| Title |
| Casting & The Effect of the Bi on the Microstructure of Rapidly Solidified Ag-Sn-In Alloys |
| 김정수 Jung Su Kim , 남태운 Tae Woon Nam , 권기봉 Gi Bong Kwon , 조대형 Dae Hyoung Cho , 장대정 Dae Jung Jang |
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| Abstract |
| Contact material is widely used as electrical parts. Ag-CdO has a good wear resistance and stable contact resistance. But the disadvantages of Ag-CdO alloy are coarse Cd oxides and harmful metal, Cd. Then Ag-Sn alloy that has stable and fine Sn oxide at high temperature has been developed. In order to investigate the effect of Bi addition that affects the formation of the oxide layer on the surface and the formation of oxide in matrix Ag, we studied the microstructures and properties of Ag-Sn-In(-Bi) material fabricated by rapid solidification process. The experimental procedures were melting using high frequency induction, melt spinning, and internal oxidation. We have shown that the size of Sn oxide at no additional Bi is 20nm and the effect of Bi for high hardness is 0.3wt%Bi. Bi was concentrated to grain boundary and Bi made precipitation free zone (PFZ). Then Bi caused poor properties of alloy. |
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| Key Words |
| contact material, internal oxidation, oxide particle, Ag-Sn, rapid solidification process, Bi |
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