As-cast 및 급속응고한 Mn48(Cu8-xFex)Al44 및 (Mn48-xFex)Cu8Al44 합금계의 자기적 특성 및 결정구조에 관한 연구

Abstract

주조상태 및 급속응고한 Mn48(Cu8-xFex)Al44 와 (Mn48-xFex)Cu8Al44 합금계의 결정구조 및 자기적 특성을 조사하였다. 두 합금계열 모두 τ-상과 κ-상의 혼합상으로 나타났는데 Fe양이 작을때는(x≤4) τ-상과 κ-상, x가 2 이상이면 Fe가 Cu를 대치한 Mn48(Cu8-xFex)Al44 합금계에서는 γ₂-상, β-Mn상, τ-상의 혼합상, Fe가 Mn을 대치하고 Cu를 함유하고 있는 (Mn48-xFex)Cu8Al44 합금계에서는 κ-상만이 나타났다. Mn48(Cu8-xFex)Al44 합금계는 주조상태에서는 Fe양(x)이 증가함에 따라 포화자화값(σ0.0)이 감소하고 큐리온도(Tc)가 증가하는데, 급속응고시편은 그 반대의 현상을 나타내었다. (Mn48-xFex)Cu8Al44 합금계는 주조상태에서는 σ0.0 및 Tc가 Fe양에 따라 규칙적인 변화를 보이지 않고 각각 41.0∼59.0(emu/g) 및 430∼590(K)의 범위에 있으나, 금속응고시편에서는 Fe양에 따라 σ0.0와 Tc가 함께 감소하였다. 두 합금계의 급속응고 시편에서는 Mn48(Cu8-xFex)Al44합금계가 미량의 τ상을 보여준 것을 제외하고는 κ-상으로 나타났다.

Magnetic properties and crystal structures of as-cast and rapidly solidified Mn48(Cu8-xFex)Al44 and (Mn48-xFex)Cu8Al44 alloys have been investigated using X-ray diffractometer, optical microscopy and vibrating sample magnetometer. Magnetic properties of the Mn48(Cu8-xFex)Al44 and (Mn48-xFex)Cu8Al44 alloys were found to be determined by the relative fraction of ferromagnetic τ- and κ-phases. In as-cast Mn48(Cu8-xFex)Al44 alloys, as x increased, saturation magnetization (σ0.0) decreased and curie temperature (Tc) increased. In rapidly solidified Mn48(Cu8-xFex)Al44 alloys, magnetic properties showed that σ0.0 and Tc have 41.0∼59.0 (emu/g) and 430∼590 (K), respectively. In rapidly solidified (Mn48-xFex)Cu8Al44 alloys, as x increased σ0.0 and Tc decreased. As-cast (Mn48-xFex)Cu8Al44 specimens showed that alloys with x=2 and 4 consisted of τ- and κ-phases, and alloys with x=6 γ₂, β-Mn and τ-phases. As-cast Mn48(Cu8-xFex)Al44 alloys showed that alloys with x=2 and 4 consisted of τ- and κ-phases and alloys with x=6 and 8, single κ-phase. Rapidly solidified specimens of both Mn48(Cu8-xFex)Al44 and (Mn48-xFex)Cu8Al44 alloys showed single κ-phase except that Mn48(Cu8-xFex)Al44 alloys showed weak traces of τ-phases.

Magnetic properties and crystal structures of as-cast and rapidly solidified Mn48(Cu8-xFex)Al44 and (Mn48-xFex)Cu8Al44 alloys have been investigated using X-ray diffractometer, optical microscopy and vibrating sample magnetometer. Magnetic properties of the Mn48(Cu8-xFex)Al44 and (Mn48-xFex)Cu8Al44 alloys were found to be determined by the relative fraction of ferromagnetic τ- and κ-phases. In as-cast Mn48(Cu8-xFex)Al44 alloys, as x increased, saturation magnetization (σ0.0) decreased and curie temperature (Tc) increased. In rapidly solidified Mn48(Cu8-xFex)Al44 alloys, magnetic properties showed that σ0.0 and Tc have 41.0∼59.0 (emu/g) and 430∼590 (K), respectively. In rapidly solidified (Mn48-xFex)Cu8Al44 alloys, as x increased σ0.0 and Tc decreased. As-cast (Mn48-xFex)Cu8Al44 specimens showed that alloys with x=2 and 4 consisted of τ- and κ-phases, and alloys with x=6 γ₂, β-Mn and τ-phases. As-cast Mn48(Cu8-xFex)Al44 alloys showed that alloys with x=2 and 4 consisted of τ- and κ-phases and alloys with x=6 and 8, single κ-phase. Rapidly solidified specimens of both Mn48(Cu8-xFex)Al44 and (Mn48-xFex)Cu8Al44 alloys showed single κ-phase except that Mn48(Cu8-xFex)Al44 alloys showed weak traces of τ-phases.