Pramana | |
On amorphization and nanocomposite formation in Al–Ni–Ti system by mechanical alloying | |
K Das2  B S Murty1  G K Dey3  S K Pabi12  | |
[1] Metallurgical and Materials Engineering Department, Indian Institute of Technology- Madras, Chennai 600 036, India$$;Metallurgical and Materials Engineering Department, Indian Institute of Technology, Kharagpur 721 302, India$$;Bhabha Atomic Research Centre, Mumbai 400 085, India$$ | |
关键词: Nanocomposite; amorphization; mechanical alloying; Miedema model; Al– Ni–Ti system.; | |
DOI : | |
学科分类:物理(综合) | |
来源: Indian Academy of Sciences | |
【 摘 要 】
Amorphous structure generated by mechanical alloying (MA) is often used as a precursor for generating nanocomposites through controlled devitrification. The amorphous forming composition range of ternary Al–Ni–Ti system was calculated using the extended Miedema's semi-empirical model. Eleven compositions of this system showing a wide range of negative enthalpy of mixing (−𛥠ð»mix) and amorphization (−𛥠ð»amor) of the constituent elements were selected for synthesis by MA. The Al88Ni6Ti6 alloy with relatively small negative 𛥠ð»mix (−0.4 kJ/mol) and 𛥠ð»amor (−14.8 kJ/mol) became completely amorphous after 120 h of milling, which is possibly the first report of complete amorphization of an Al-based rare earth element free Al–TM–TM system (TM = transition metal) by MA. The alloys of other compositions selected had much more negative 𛥠ð»mix and 𛥠ð»amor; but they yielded either nanocomposites of partial amorphous and crystalline structure or no amorphous phase at all in the as-milled condition, evidencing a high degree of stability of the intermetallic phases under the MA environment. Hence, the negative 𛥠ð»mix and 𛥠ð»amor are not so reliable for predicting the amorphization in the present system by MA.
【 授权许可】
Unknown
【 预 览 】
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