Affiliation:
1. Karpagam Academy Of Higher Education
2. PSG College of Arts and Science, Department of Physics
3. Karpagam Academy of Higher Education (KAHE), Department of M
Abstract
<div class="section abstract"><div class="htmlview paragraph">Effect of Lanthanum addition on mechanical properties of LA93 along with its
microstructural evolution has been analysed using optical microscopy, scanning
electron microscope (SEM) and energy dispersive spectroscopy (EDS). The phases
of this alloy were identified by X-ray diffraction (XRD). La addition has
resulted in a reformed semi continuous structure with a decrease in grain volume
along the boundary. The morphology shows the formation of Al<sub>2</sub>La and
Al<sub>3</sub>La phase while the AlLi in LA93 has decreased. At 1.5 wt% La
addition, the maximum grain refinement is obtained. In LA93+xLa, the
Al<sub>2</sub>La and Al<sub>3</sub>La appear as a white long stripy phase
and a white large blocky phase, respectively, and contribute to the increased
strength of the alloy. There is a clear distribution of intermetallic compounds
along the grain boundary of α-Mg and inside the matrix. The ultimate tensile
strength increases by 60% to 112 MPa and hardness increases by 48% when the La
content is 1.5 wt%. This improvement can be attributed to the precipitation of
intermetallic compounds and grain refinement of β-phase which impede the
dislocation motion. The elongation also increased considerably with the
lanthanum addition.</div></div>