The corrosion behaviors of Mg-7Gd-5Y-1Nd-0.5Zr alloy under (NH₄)₂SO₄, NaCl and Ca(NO₃)₂ salts spray condition

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• 作者：Quantong Jiang ; Kui Zhang ; Xinggang Li ; Yongjun Li ; Minglong Ma ; Guoliang Shi ; Jiawei Yuan
• 关键词：EW75 magnesium alloy ; Corrosion behaviors ; Salt spray ; PH value
• 刊名：Journal of Magnesium and Alloys
• 出版年：September, 2013
• 年：2013
• 卷：1
• 期：3
• 页码：230-234
• 全文大小：1060 K

文摘

The corrosion behaviors of Mg-7Gd-5Y-1Nd-0.5Zr alloys after T5 treatment under (NH₄)₂SO₄, NaCl and Ca(NO₃)₂ salt spray condition were investigated by weight loss rates, residual mechanical properties, scanning electron microscope (SEM), X-ray Diffraction (XRD) and potentiodynamic polarization tests. The corrosion degree of Mg-7Gd-5Y-1Nd-0.5Zr alloys in Ca(NO₃)₂ salt spray was very shallow by corrosion morphology and the corrosion route was extended along the surface in texture-like shape, while the alloy in NaCl and (NH₄)₂SO₄ salt spray were major local corrosion and there were serious corrosion pits on the surface. The weight loss rates in (NH₄)₂SO₄, NaCl and Ca(NO₃)₂ salt spray was respectively 0.4147, 0.1618 and 0.0725聽mg/(cm²聽d^鈭?). The results of residual mechanical properties indicated that the corrosion order in salts spray of Mg-7Gd-5Y-1Nd-0.5Zr alloys is NH₄SO₄聽>聽NaCl聽>聽Ca(NO₃)₂, which was consistent with the results of potentiodynamic polarization tests. The type of the salts will play a vital role in the initiation of the corrosion of EW75 alloy when they are used in the atmosphere environments. Inorganic salts with the smaller PH value after dissolution will have a stronger impact on the corrosion of EW75 magnesium alloys.