In this work, the wetting phase transition of grain boundaries (GBs) and their triple junctions (GB TJs) by the second solid phase in the magnesium-based alloy EZ33A is studied. The condition for complete wetting for the GB TJ (\(\left({{\sigma _{{\rm{GB}}}}>\sqrt3{\sigma _{{\rm{SS}}}}}\right)\)) is weaker than that for GBs (σ_GB > 2σ_SS). Therefore, if the transition from partial to complete wetting occurs with increasing temperature, then all GB TJs should become completely wetted at a temperature T_wTJ, which is lower than the temperature T_wGB, at which all GBs become completely wetted. For the first time, it was experimentally found that GB TJs are completely wetted at T_wTJ = 380±10 °C, which is approximately 70 °Clower than T_wGB = 450 ± 10 °C. The wetting phase at the GBs is the intermetallic compound (Mg, Zn)₁₂RE. A similar phenomenon was previously observed for GB TJ wetting with a liquid phase [B. B. Straumal, O. Kogtenkova, and P. Zieba, Acta Mater. 56, 925 (2008)].

在这项工作中，研究了镁基合金EZ33A中晶界（GBs）及其三重结（GB TJs）的第二固相的润湿相变。GB TJ完全润湿的条件（\（\ left（{{\ sigma _ {{\ rm {GB}}}}> \ sqrt3 {\ sigma _ {{\ rm {SS}}}}} \\ right ）\） ）比为GBS较弱（σ _GB > 2 σ _SS）。因此，如果从部分到完全润湿的过渡随温度升高发生时，那么所有的GB紧密连接应该成为完全在温度润湿Ť _WTJ，这比温度T下_WGB，所有GB都被完全浸湿。首次通过实验发现，GB TJ在T _wTJ = 380±10°C时被完全润湿，比T _wGB = 450±10°C低约70° 。GBs处的润湿相是金属间化合物（Mg，Zn）₁₂ RE。以前在使用液相的GB TJ润湿中观察到类似现象[BB Straumal，O. Kogtenkova和P. Zieba，Acta Mater。56，925（2008）]。