On amorphization and nanocomposite formation in Al–Ni–Ti system by mechanical alloying

Pramana

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 (−𝛥 𝐻mix) and amorphization (−𝛥 𝐻amor) of the constituent elements were selected for synthesis by MA. The Al88Ni6Ti6 alloy with relatively small negative 𝛥 𝐻mix (−0.4 kJ/mol) and 𝛥 𝐻amor (−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 𝛥 𝐻mix and 𝛥 𝐻amor; 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 𝛥 𝐻mix and 𝛥 𝐻amor are not so reliable for predicting the amorphization in the present system by MA.

【 授权许可】

Unknown