Effect of Hydrogen on Surface Morphology and Mechanical Properties of As-cast Mg-14Li Alloy
-
摘要: 对铸态Mg-14Li合金进行阴极充氢，充氢时间在0～18 h，对比分析了充氢前后合金的表面形貌和拉伸性能。结果表明：阴极充氢后，铸态Mg-14Li合金表面发生点蚀，LiCO3腐蚀产物膜发生破坏；随着充氢时间的延长，腐蚀坑深度不断增加，腐蚀产物增多，但充氢后合金中无微裂纹，说明β-Li相的氢脆敏感性较低；随着充氢时间的延长，铸态Mg-14Li合金的屈服强度、抗拉强度和断后伸长率下降，拉伸断口上的韧窝数量减少，解理面增多，合金断裂模式从韧性断裂转变为脆性断裂。Abstract: Cathodic hydrogen charging was conducted on the as-cast Mg-14Li alloy with hydrogen charging times of 0-18 h.The surface morphology and tensile properties of the alloy before and after hydrogen charging were compared and analyzed.The results show that pitting corrosion occurred on the surface of as-cast Mg-14Li alloy after cathodic hydrogen charging, and the LiCO3 corrosion product film was destroyed.The depth of corrosion pits and the quantity of corrosion products increased with the hydrogen charging time.However, no microcracks were found in the alloy after hydrogen charging, indicating that the hydrogen embrittlement sensitivity of β-Li phase was low.With the increase of hydrogen charging time, the yield strength, tensile strength and percentage elongation after fracture of as-cast Mg-14Li alloy decreased, and the dimples on the fracture surface decreased and the cleavage surface increased in amount, indicating that the fracture mode of as-cast Mg-14Li alloy changed from ductile fracture to brittle fracture.
-
Keywords:
- Mg-Li alloy /
- cathodic hydrogen charging /
- hydrogen damage /
- tensile property
-
-
[1] XU D K,WANG B J,LI C Q,et al.Effect of icosahedral phase on the thermal stability and ageing response of a duplex structured Mg-Li alloy[J].Materials & Design,2015,69:124-129.
[2] XU D K,LI C Q,WANG B J,et al.Effect of icosahedral phase on the crystallographic texture and mechanical anisotropy of duplex structured Mg-Li alloys[J].Materials & Design,2015,88:88-97.
[3] NAYEB-HASHEMI A A,CLARK J B,PELTON A D.The Li-Mg (lithium-magnesium)system[J].Bulletin of Alloy Phase Diagrams,1984,5(4):365-374.
[4] SON H T,KIM Y H,KIM D W,et al.Effects of Li addition on the microstructure and mechanical properties of Mg-3Zn-1Sn-0.4Mn based alloys[J].Journal of Alloys and Compounds,2013,564:130-137.
[5] ZENG R C,SUN L,ZHENG Y F,et al.Corrosion and characterisation of dual phase Mg-Li-Ca alloy in Hank's solution:The influence of microstructural features[J].Corrosion Science,2014,79:69-82.
[6] SONG G L,ATRENS A.Corrosion mechanisms of magnesium alloys[J].Advanced Engineering Materials,1999,1(1):11-33.
[7] CHMIELA B,MOCICKI A,SOZASKA M.Investigation of stress corrosion cracking in magnesium alloys[J].Solid State Phenomena,2013,211:89-92.
[8] SONG R G,BLAWERT C,DIETZEL W,et al.A study on stress corrosion cracking and hydrogen embrittlement of AZ31 magnesium alloy[J].Materials Science and Engineering:A,2005,399(1/2):308-317.
[9] WINZER N,ATRENS A,DIETZEL W,et al.Fractography of stress corrosion cracking of Mg-Al alloys[J].Metallurgical and Materials Transactions A,2008,39(5):1157-1173.
[10] WINZER N,ATRENS A,SONG G,et al.A critical review of the stress corrosion cracking (SCC)of magnesium alloys[J].Advanced Engineering Materials,2005,7(8):659-693.
[11] MAKAR G L,KRUGER J,SIERADZKI K.Stress corrosion cracking of rapidly solidified magnesium-aluminum alloys[J].Corrosion Science,1993,34(8):1311-1342.
[12] KAPPES M,IANNUZZI M,CARRANZA R M.Hydrogen embrittlement of magnesium and magnesium alloys:A review[J].Journal of the Electrochemical Society,2013,160(4):168-178.
[13] HORSTMAN R,PETERS K A,GEBREMEDHIN S,et al.Techniques for determination of the crystallographic characteristics of environmentally induced brittle fractures[J].Journal of Testing and Evaluation,1984,12(3):142-148.
[14] CHEN J,WANG J Q,HAN E H,et al.Electrochemical corrosion and mechanical behaviors of the charged magnesium[J].Materials Science and Engineering:A,2008,494(1/2):257-262.
[15] CHEN J,WANG J Q,HAN E H,et al.Effect of hydrogen on corrosion and stress corrosion cracking of AZ91 alloy in aqueous solutions[J].Acta Metallurgica Sinica (English Letters),2016,29(1):1-7.
[16] CHEN J,WANG J Q,HAN E H,et al.States and transport of hydrogen in the corrosion process of an AZ91 magnesium alloy in aqueous solution[J].Corrosion Science,2008,50(5):1292-1305.
[17] XU W Q,BIRBILIS N,SHA G,et al.A high-specific-strength and corrosion-resistant magnesium alloy[J].Nature Materials,2015,14(12):1229-1235.
[18] TAL-GUTELMACHER E, ELIEZER D.The hydrogen embrittlement of titanium-based alloys [J].JOM, 2005, 57(9):46-49.
[19] SONG Y W,SHAN D Y,CHEN R S,et al.Investigation of surface oxide film on magnesium lithium alloy[J].Journal of Alloys and Compounds,2009,484(1/2):585-590.
[20] LI C Q,XU D K,CHEN X B,et al.Composition and microstructure dependent corrosion behaviour of Mg-Li alloys[J].Electrochimica Acta,2018,260:55-64.
[21] CHEN J,DONG J H,WANG J Q,et al.Effect of magnesium hydride on the corrosion behavior of an AZ91 magnesium alloy in sodium chloride solution[J].Corrosion Science,2008,50(12):3610-3614.
[22] ATRENS A,WINZER N,SONG G,et al.Stress corrosion cracking and hydrogen diffusion in magnesium[J].Advanced Engineering Materials,2006,8(8):749-751.
[23] BOBBY KANNAN M,DIETZEL W.Pitting-induced hydrogen embrittlement of magnesium-aluminium alloy[J].Materials & Design,2012,42:321-326.
计量
- 文章访问数: 6
- HTML全文浏览量: 0
- PDF下载量: 4
下载:
