PSI - Issue 13

Naoyuki Tsutsui et al. / Procedia Structural Integrity 13 (2018) 849–854 Author name / Structural Integrity Procedia 00 (2018) 000 – 000

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3. Results Typical stress – strain curves at 353 K and 423 K are shown in Fig. 3. At 353 K, where both Ga and the Bi – In eutectic alloy were liquid, they reduced the fracture strain  F significantly. The ultimate tensile stress (UTS)  UTS was also reduced, much more so when liquid Ga was used. At 423 K, where Ga, In, and both eutectic alloys were liquid, their presence resulted in lower UTS and fracture strain. Since Zn is unaffected by Bi (Shunk and Warke 1974), LME observed following contact with Bi – In and Bi – Sn alloys was due to their In and Sn contents, respectively. As shown as a function of testing temperature T in Fig. 4, in the case of the Bi – In alloy, LME occurred above the eutectic temperature of the Bi – In system. When In was used as the embrittler, the onset temperature of LME was not the melting point of In (430 K), but the eutectic temperature of the In – Zn system (417 K).

Fig. 3. Stress – strain curves of polycrystalline Zn in contact with liquid metals at (a) 353 K, and (b) 423 K. The liquid metal species are indicated in the figure.

Fig. 4. Temperature dependence of (a) ultimate tensile stress  UTS , and (b) fracture strain  F. The liquid metal species are indicated in the figure. The eutectic temperatures of the Bi – In system T Be i−In and In – Zn system T I e n−Zn are also shown.