• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.246-249
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• 2000

The effects of Zr on the mechanical workability and tensile strength of Cu-Ni-Mn-Sn-Al alloys have been investigated and the following results were obtained. The mechanical workability of Cu-Ni-Mn-Sn-Al alloys are increased with addition of Zr. And the surface cracks of specimen were not produced in Zr added Alloys. Especially in condition of hot-worked beyond the 90% working ratio, Zr contained specimen showed intra-granule crack propagation but Zr-free specimen showed inter-granule mode. The tensile strength have maximum value in 0.05% Zr contained alloy. The aging mechanism of Cu-Ni-Mn-Sn-Al alloys were varied by Zr addition.

• Advances in materials Research
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• v.9 no.4
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• pp.323-335
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• 2020

This article reviews findings and progresses in the past decade on manganese-aluminium (MnAl) based magnets as the interest has been revived to fulfill their potential as commercial magnets. The challenges in developments of these rare-earth-free magnets are to acquire a high remanence and coercivity from the ferromagnetic τ-phase in MnAl alloys. To this end, the phase transformation to this τ-MnAl with L10 body centered tetragonal structure has been promoted by a variety of methods and a few percents of carbon (C) is often added to prevent the phase decomposition. Magnetization and coercivity are not only influenced by the phase composition but also the microstructure. The fabrication processes and factors affecting the phase and microstructure are therefore covered. Finally, the productions of bulk MnAl magnets are addressed.

• Journal of Korea Foundry Society
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• v.12 no.2
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• pp.139-148
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• 1992

The mechanical properties of Ti-Al intermetallic compounds which contain Mn, Zr, or Cr as the third element have been evaluated by means of hardness and compression tests. Microstructures have also been examined using an optical microscope. The cast structures of Ti-Al alloys are coarsened and the lamellar volume fraction is increased by the additions of Mn or V, but the cast structures are refined by the addition of Zr. Hardness tests of room temperature and compression tests at $600^{\circ}C$ showed that the mechanical properties of Ti-Al alloys were mainly dependent on the volume fraction of the ${\alpha}_2$ phase, grain size and solid solution hardening. However according to the compression test at $1000^{\circ}C$, the yield strength of Ti-Al alloys decreased with an increase in Mn or Cr content, but increased with an increase in the Zr content.

• Journal of Korea Foundry Society
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• v.23 no.3
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• pp.153-157
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• 2003

본 논문은 레오캐스팅용 AZ91 합금 슬러리를 제조하는 새로운 방법에 관한 것이다. 그 원리는 AZ91 합금 액상에서 Mn의 용해도차에 의해 생성되는 $Al_8(Mn,Fe)_5$ 정출물을 ${\alpha}-Mg$ 초정 생성을 위한 불균일 핵생성 자리로 사용하고자 하는 것이다. 제조된 슬러리의 미세조직 분석결과 $Al_8(Mn,Fe)_5$ 정출물이 ${\alpha}-Mg$ 내에 위치하고 있어, 이로부터 정출물이 효과적으로 불균일 핵생성 자리로 작용하고 있음을 알 수 있었다. 또한 Mn 함량의 증가는 $Al_8(Mn,Fe)_5$ 정출물 수를 증가시켜 고상분율이 일정할 때 슬러리 내 ${\alpha}-Mg$ 고상의 크기를 감소시키고 구형도를 향상시킨다. 이외에도 냉각속도 및 유지시간이 슬러리 미세조직에 미치는 영향에 대해서도 보고하였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.05a
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• pp.76-76
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• 2002

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 1997.10a
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• pp.12-13
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• 1997

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.281-284
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• 2004

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.05a
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• pp.131-131
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• 2001

• Proceedings of the Korean Magnestics Society Conference
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• 2003.06a
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• pp.80-81
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• 2003

• Proceedings of the Materials Research Society of Korea Conference
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• 1993.11a
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• pp.41-41
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• 1993