Effect of Nd on microstructure and mechanical properties of dual-phase Mg-9Li-3Al alloys. (12th April 2019)

• Record Type: Journal Article
• Authors: Xu, Tiancai; Shen, Xia; Li, Boxin; Peng, Xiaodong; Liu, Qingcai; Wei, Guobing; Liu, Gang; Ma, Zhenduo
• Is Part Of: Materials research express. Volume 6:Number 7(2019)
• Publication Date: 2019-04-12
• Subjects: Mg-Li alloy -- duplex structure -- Nd addition -- microstructure -- mechanical properties; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/ab1543
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: The as-cast dual-phase Mg-9Li-3Al-xNd (x = 0, 0.5, 1.0, 1.5, 2.0 and 3.0 wt%, LA93-xNd) alloys were designed and prepared by vacuum melting, then the as-cast alloys processed by hot extrusion. The microstructures and mechanical properties of as-cast and as-extruded LA93-xNd alloys were investigated by the optical microscope (OM), x-ray diffraction (XRD), scanning electron microscope (SEM) with an Oxford energy-dispersive x-ray spectroscope (EDS), transmission electrical microscope (TEM) and uniaxial tension test. The addition of Nd led to the most significant grain refinement of Mg-9Li-3Al (LA93) alloy. The as-cast LA93 alloy was composed of α -Mg phase, β -Li phase and Li2 MgAl intermetallic compound, and that Al2 Nd and Al11 Nd3 intermetallic compound generated when Nd added into the alloy. Nd was used to strengthen LA93 alloy by means of solid solution, grain refinement and precipitation. Among as-cast alloys, the tensile strength and elongation of LA93-1.0Nd alloy were the most outstanding, the tensile strength was 173 Mpa and the elongation was 36.8%. The mechanical properties of Mg-Li-Al-Nd alloy in extruded state was greatly improved compared with that in cast state, which was mainly because the extrusion weakened the defects left from cast state and improved the quality of alloy. The extruded alloy grains had been significantly refined. The ultimate tensile strength and elongation of as-extruded LA93-1.0Nd and LA93-1.5Nd alloys were 239 MPa and 27%, 255 MPa and 21%, respectively.