Fig. 1 The heating ways for DSC (a) non-isothermal; (b) isothermal analyses

10 K/min

873 K , 300 sec.

313 K , 600 sec.

Tem

pera

ture

(K

)

Time (sec.)

313 K , 600 sec.

40 K/min

sec.

30 K/min 10 K/min

313 K , 600 sec.313 K , 600 sec.

Tem

pera

ture

(K

)

Time (sec.)

K ,(a) (b)

Study of Thermal Properties in Zr-Al-Cu-Ni Amorphous Alloy by Adding Boron and Silicon

J.C. Huang(黃志青 )1 ＊ T.H. Hung(洪子翔 )1 Jason S.C. Jang(鄭憲清 )2 S.C. Lu(盧斯誠 )2

1 Institute of Materials Science and Engineering, National Sun Yat-Sen University( 中山大學材料科學研究所 )

2 Department of Material Science and Engineering, I-Shou University(義守大學材料科學與工程學系 )

Abstract We report the study of thermal properties in Zr-Al-Cu-Ni multi-components amorphous alloys by adding boron and silicon. According to the results of the experiments, the Zr60Al7.5Cu17.5Ni10B1Si4

amorphous alloy ribbons with the highest GFA index value) and the value is 0.42; the maximum supercooled liquid region (Tx) is about 85 K for the Zr60Al7.5Cu17.5Ni10B1Si4 amorphous alloy ribbons.

For the isothermal analyses or non-isothermal analyses, the Avrami index (n value) is not constant, and the Zr60Al7.5Cu17.5Ni10B1Si4amorphous alloy ribbons with the largest activation energy, which is

more than 300 kJ/mol.

Experimental Procedures

The Chemical compositions of the alloys for this study were Zr65-X-YAl7.5Cu17.5Ni10BXSiY, X

varies from 1 to 2 and Y varies from 1 to 4 by an interval of 1. The pre-alloyed ingots were prepared by arc melting of pure elements, such as zirconium(99.8 wt.% purity), aluminum (99. wt.% purity), nickel(99.5 wt.% purity), copper (99.9 wt.% purity), boron (99.5 wt.% purity), and silicon (99.999 wt.% purity), in an argon atmosphere. The ribbon samples of about about 80 to 100 m in thickness and 5 mm in width were prepare by a single roller melt-spinning technique in an argon atmosphere. The as-quench structure was examined by X-ray diffraction (XRD), and the thermal properties was analyzed by differential scanning calorimeter(DSC). There are two different heating ways for the analysis of thermal properties, as shown in Fig. 1.

Results

● Non-isothermal analysis:

Fig. 2 The XRD patterns of the Zr65-X-

YAl7.5Cu17.5Ni10BXSiY alloysFig. 3 The XRD patterns of the Zr65-

X-YAl7.5Cu17.5Ni10BXSiY alloys

Fig. 4 The Tx range and value of

the Zr65-X-YAl7.5Cu17.5Ni10BXSiY alloys

Fig. 5 The plot of n value vs. temperature

(b)(a)

Fig. 6 The plot of ln[-ln(1-x)]vs.1/T (a) Zr60Al7.5Cu17.5Ni10B1Si4; (b) Zr62Al7.5Cu17.5Ni10B2Si1

Fig. 7 The relationship of activity energy between nucleation and growth for Zr60Al7.5Cu17.5Ni10B1Si4 and Zr62Al7.5Cu17.5Ni10B2Si1

● Isothermal analysis:

Conclusion

(1)The Zr60Al7.5Cu17.5Ni10B1Si4 amorphous alloy ribbons with the highest GFA index value)

and the value is 0.42.

(2)The maximum supercooled liquid region (Tx) is about 85 K for the Zr60Al7.5Cu17.5Ni10B1Si4

amorphous alloy ribbons.

(3) For the non-isothermal and isothermal analysis, the Avrami index (n value) is not constant, and the Zr60Al7.5Cu17.5Ni10B1Si4amorphous alloy ribbons with the largest activation energy,

which is 400 to 500 kJ/mol and 300 to 500 kJ/mol, respectively.

Fig. 8 The relationship between crystallity and Isothermal time for (a) Zr60Al7.5Cu17.5Ni10B1Si4 ; (b) Zr62Al7.5Cu17.5Ni10B2Si1

(b)(a)

Fig. 9 The plot of ln[-ln(1-x)] vs. lnt for (a) Zr60Al7.5Cu17.5Ni10B1Si4 ;

(b) Zr62Al7.5Cu17.5Ni10B2Si1

(a) (b)

(a) (b)

Fig. 10 The plot of lnt vs.1/T for (a) Zr60Al7.5Cu17.5Ni10B1Si4 ;

(b) Zr62Al7.5Cu17.5Ni10B2Si1