Devitrification of rapidly quenched Al�?�Cu�?�Ti amorphous alloys

[摘要] X-ray diffraction, transmission electron microscopy and differential scanning calorimetry were carried out to study the transformation from amorphous to icosahedral/crystalline phases in the rapidly quenched Al₅₀Cu₄₅Ti₅ and Al₄₅Cu₄₅Ti₁₀ alloys. In the present investigation, we have studied the formation and stability of amorphous phase in Al₅₀Cu₄₅Ti₅ and Al₄₅Cu₄₅Ti₁₀ rapidly quenched alloys. The DSC curve shows a broad complex type of exothermic overlapping peaks (288â€�??550°C) for Al₅₀Cu₄₅Ti₅ and a well defined peak around 373°C for Al₄₅Cu₄₅Ti₁₀ alloy. In the case of Al₅₀Cu₄₅Ti₅ alloy amorphous to icosahedral phase transformation has been observed after annealing at 280°C for 73 h. Large dendritic growth of icosahedral phase along with ð›�?-Al phase has been found. Annealing of Al₅₀Cu₄₅Ti₅ alloy at 400°C for 8 h results in formation of Al₃Ti type phase. Al₄₅Cu₄₅Ti₁₀ amorphous alloy is more stable in comparison to Al₅₀Cu₄₅Ti₅ alloy and after annealing at 400°C for 8 h it also transforms to Al₃Ti type phase. However, this alloy does not show amorphous to icosahedral phase transformation.

[学科分类] 材料工程

[关键词] Amorphous phase;icosahedral phase;crystallization.