Microstructure and Mechanical Properties of Tip /TiB2p and Hybrid Reinforced Magnesium Matrix Composites
Author of the article: GUOGuanghui, GUO Wenbo, LYUShulin, XIANG Kewang, YAN Zhaoxiang, MAOYouwu,WUShusen
Author's Workplace:National KeyLaboratoryofFormingand MoldTechnology, SchoolofMaterialsScience and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Key Words:magnesium matrix composites; hybrid reinforcement; microstructure; mechanical properties; hot extrusion; continuous squeeze casting-extrusion
Abstract:
Hybrid reinforced magnesium matrix composites incorporate two or more reinforcement phases with different
properties into the matrix, leveraging the advantages of each reinforcement phase and the matrix to achieve composites with
excellent comprehensive performance. This study investigated the effects of squeeze casting and continuous squeeze
casting-extrusion on the microstructure and mechanical properties of 0.5 wt.% Tip
/AZXW9100, 0.5 wt.% TiB2p
/AZXW9100,
and 0.5 wt.% Tip
+0.5 wt.% TiB2p
/AZXW9100 magnesium matrix composites. The results show that the addition of either
0.5 wt.% Tip
or 0.5 wt.% TiB2p
alone can refine the as-cast matrix grains of the composites. The most significant grain
refinement effect (from 118.25 μm to 53.79 μm) is achieved when 0.5 wt.% Tip
and 0.5 wt.% TiB2p
are added together.
With the addition of 0.5 wt.% Tip
, the β-Mg17
Al12
phase in the composite is significantly refined, and the area fraction of the
second phase decreases compared with that of the matrix alloy, becoming the lowest among the three materials. In contrast,
the addition of 0.5 wt.% TiB2p
increases the size of the β-Mg17
Al12
phase and results in the highest second-phase area
fraction. When 0.5 wt.% Tip
and 0.5 wt.% TiB2p
are added together, the β-Mg17
Al12
phase is significantly refined compared
with the addition of 0.5 wt.% TiB2p
alone, and the second-phase area fraction (5.175%) lies between that of the individual
additions of 0.5 wt.% TiB2p
(5.694%) and 0.5 wt.% Tip
(3.642%), although it remains higher than that of the matrix alloy (4.433%). The addition of Tip
or TiB2p
alone weakens the texture strength of the matrix, whereas the combined addition of
0.5 wt.% Tip
+0.5 wt.% TiB2p
results in the lowest matrix texture strength. The addition of 0.5 wt.% TiB2p
improves the
strength of the composite but reduces its elongation. In contrast, the addition of 0.5 wt.% Tip
slightly increases the strength
but significantly improves the elongation. When 0.5 wt.% Tip
and 0.5 wt.% TiB2p
are added together, the composite achieves
a yield strength of 211 MPa and a tensile strength of 318 MPa, representing increases of 13.4% and 7.4%, respectively,
compared with those of the matrix alloy, while maintaining an elongation of 14.9%. This demonstrates a combination of
high strength and excellent toughness.