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Preparation and characterization of high damage-tolerance nacre-inspired magnesium alloy matrix composites with high carbon nanotube contents.
- Source :
-
Carbon . Jun2020, Vol. 162, p382-391. 10p. - Publication Year :
- 2020
-
Abstract
- A nacre-like magnesium matrix composite with high carbon nanotube (CNT) contents (up to 4.40 wt%) was successfully prepared under the combined effects of bidirectional freeze casting, pressureless infiltration, and hot pressing. The bidirectional freeze casting was carried out to fabricate large-scale parallelly layered CNT scaffolds. The spontaneous infiltration of an AZ91 magnesium alloy was achieved using nano-silica as the wetting promoter, and MgO and Mg 2 Si (reaction products) provided the strength of the as-synthesized composites. Furthermore, the hot pressing increased the average thickness ratio of reinforcing phase/alloy layers in the AZ91/CNT composites from 0.89 (before hot pressing) to 1.46 (after hot pressing) and also significantly improved the specific strength from 142.3 MPa/(g⋅cm−3) to 158.7 MPa/(g⋅cm−3) without sacrificing the specific toughness ((17–18) MPa⋅m1/2/(g⋅cm−3)). The resultant composites were mainly strengthened by CNTs, reaction products, and the strong interfacial bonding between CNTs and the Mg matrix. The key toughening mechanisms for the as-prepared composites were crack deflection, branching, and CNT pull-out. This study provides a new idea for the economical and efficient preparation of lightweight and damage-tolerant composites with high CNT contents. Image 1091852 [ABSTRACT FROM AUTHOR]
- Subjects :
- *CARBON composites
*MAGNESIUM alloys
*HOT pressing
*INTERFACIAL bonding
Subjects
Details
- Language :
- English
- ISSN :
- 00086223
- Volume :
- 162
- Database :
- Academic Search Index
- Journal :
- Carbon
- Publication Type :
- Academic Journal
- Accession number :
- 142702903
- Full Text :
- https://doi.org/10.1016/j.carbon.2020.02.072