Al-Al₂O₃ 粒子强化 複合材料에 있어서 合金組成에 따른 微細組織의 變化

다국어 초록 (Multilingual Abstract)

Al- Al₂O₃particulate reinforced composites were investigated. The effect of alloying elements was studied for their microstructural features, dispersion behaviors, reaction products at the interface, concentration lamellas of alloying elements around particles and microhardness from matrix to matrix/particle interface. Al-Al₂O₃composites were prepared by compocasting methed.
The results are as follows: for homogeneous dispersion of Al₂O₃ particles in the matrix, a certain amount Mg or Ca are required. Those are 0.3 wt.% Mg or 0.1 wt.% Ca. In the case of Al-Cu/ Al₂O₃composite, some Alp03 particles coagulated in the grain seem to form chain-like structure.
The presence of Al₂O₃particles in Al-Si/Al₂O₃composite tends to change the acicular eutectic silicons for equiaxed eutectic silicons. X-ray diffraction studies reveal that some reaction products were formed by certain chemical reactions at the matrix/particles interfaces. The reaction products were Mg Al₂O₃, CaAl₂O₄, Al₂SiO_5, CaO, Mgo, CaAl₄O_7, Cu₂MgO₃and so on. Those phases were thought to improve the wettability and to uniform dispersion of Al₂O₃particles in the matrix. The concentration lamellas of alloying elements were observed around particles by EPMA. The microhardness of the matrix/particles interfaces is higher than that of matrix due to those reaction products.

목차 (Table of Contents)

• 목차
• ABSTRACT
• 1. 서론 = 1
• 2. 실험방법 = 3
• 2.1 시편의 제조 = 4
• 2.2 조직관찰 및 분산성 평가 = 7
• 2.3 X선 분석 = 7
• 2.4 경도 측정 = 8
• 3. 실험 결과 및 고찰 = 9
• 3.1 합금조성에 따른 분산성 변화 = 9
• 3.2 합금조성에 따른 미세조직의 변화 = 14
• 3.3 X선 회절에 의한 반응 생성물의 분석 = 21
• 3.4 미소 경도의 변화 = 25
• 4. 결론 = 31
• 참고문헌 = 32