Zr-Ti-Nb-Cu-Ni-Be계 비정질 합금에 미치는 Sn의 영향

Abstract

Abstract

Zr which is the main element of the Zr-Ti-Nb-Cu-Ni-Be amorphous alloy is very expensive and not so easy to get in the market. In this study, low cost Zircaloy (Sn 0.5~2%) instead of Zr was attempted to use in the industry field. In the Zr-Ti-Nb-Cu-Ni-Be amorphous alloy, Nb was replaced with Sn (0wt.%, 25wt.%, 50wt.%, and 100wt.%) and amorphous formability was investigated using XRD, DSC and DTA and compression test was carried out to observe the change of mechanical properties. XRD result showed the halo pattern in the diffraction angle of 30°∼40° in the 0%Sn specimen. In the DSC test, glass transition phenomenon was observed with Tg=630K, Tx=674K and ∆T=44K and Tm was 984K. Compression strength tested was 1,504MPa, and hardness was Hv521. Fracture surface showed a vein pattern which was a typical amorphous failure mode. In the 25%Sn and 50%Sn specimens, XRD results showed halo pattern and the peak for β-Zr phase. DSC results showed similar Tg and Tx to 0%Sn and Tm was 1,052K and 1,025K. The compression strength and hardness were slightly increased and fracture surface was also similar to the 0%Sn specimen which showed the vein pattern. In the 100%Sn specimen, XRD results showed the peaks for Zr5Sn3, ZrNi, Zr2Ni, Zr7Cu10 and ZrBe2 crystal phases. Tg and Tx were not revealed and Tm was 1,035K. Hardness and compression strength were Hv617 and 726MPa respectively and lower than those of the other specimens. Fracture mode was brittle. Finally, 0%Sn specimen was typical amorphous alloy, 25%Sn and 50%Sn specimens were the mixture of the amorphous and crystal phases, and 100%Sn was crystalline alloy.