Studies on crystallization behaviour and mechanical properties of Al�?�Ni�?�La metallic glasses

Bulletin of materials science

M Ghosh²  Rina Sahu²  K L Sahoo²  S Chatterjee¹ 

[1] Department of Metallurgical and Materials Engineering, Bengal Engineering and Science University, Howrah 711 103, India$$Department of Metallurgical and Materials Engineering, Bengal Engineering and Science University, Howrah 711 103, IndiaDepartment of Metallurgical and Materials Engineering, Bengal Engineering and Science University, Howrah 711 103, India$$;Metal Extraction and Forming Division, National Metallurgical Laboratory, Jamshedpur 831 007, India$$Metal Extraction and Forming Division, National Metallurgical Laboratory, Jamshedpur 831 007, IndiaMetal Extraction and Forming Division, National Metallurgical Laboratory, Jamshedpur 831 007, India$$

关键词: Metallic glass;    Alâ€�?�Niâ€�?�La alloys;    XRD;    crystallization.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

Alloy ingots with nominal composition, Al_{92â€�?�ð�?��?}Ni₈La_ð‘�? (ð‘�? = 4 to 6) and Al_{94â€�?�ð�?��?}Ni₆La_ð‘�? (ð‘�? = 6, 7), were prepared by induction melting in a purified Ar atmosphere. Each ingot was inductively re-melted and rapidly solidified ribbons were obtained by ejecting the melt onto a rotating copper wheel in an argon atmosphere. The crystallization behaviour of melt-spun amorphous ribbon was investigated by means of differential scanning calorimetry (DSC), X-ray diffractometry and transmission electron microscopy. DSC showed that Al₈₆Ni₈La₆ alloy undergoes a three-stage and rest of the alloys undergo a two-stage crystallization process upon heating. The phases responsible for each stage of crystallization were identified. During the first crystallization stage fcc-Al precipitates for low La-containing alloys and for higher La-containing alloys a bcc metastable phase precipitates. The second crystallization stage is due to formation of intermetallic compounds along with fcc-Al. Microhardness of all the ribbons was examined at different temperatures and correlated with structural evolutions. Precipitation strengthening of nano-size fcc-Al is responsible for maximum hardness in these annealed alloys.

【 授权许可】

Unknown