Balancing Strength and Ductility in Al Matrix Composites Reinforced by Few-Layered MoS2 through In-Situ Formation of Interfacial Al12Mo.

Lewen Fan,Dongdong Zhao,Fang He,Lizhuang Yang,Junwei Sha,Chunnian He,Chunsheng Shi,Liying Ma,Naiqin Zhao

doi:10.3390/ma14133561

Abstract

In this work, few-layered MoS2 (FLM) nanosheet-reinforced Al matrix composites are developed through powder metallurgy and hot extrusion. The microstructure, mechanical properties, and strengthening mechanisms have been systematically investigated. It is found that Al12Mo and Al2S3 can be formed in-situ during the sintering process, resulting in the improvement of interfacial bonding between FLM and Al matrix. With 1.5 wt.% of FLM addition, an improved tensile strength of 234 MPa with a high elongation of 17% can be obtained. Moreover, the strengthening mechanisms are also demonstrated to be grain refinement, dislocation strengthening, and load transfer, and the calculation indicates that load transfer is the main contribution factor. This work will inspire more new designs of metal matrix composites with balanced strength and ductility.

Highlights

Al matrix composites (AMCs) have attracted great attention in recent decades, and are widely used in fields including aircraft, automobile, and electronic packaging due to their high specific properties, fatigue performance, low thermal expansion coefficient, and wear coefficient [1,2,3]
Shin [13] compared the strengthening behaviors of 2D GN with that of multi-walled carbon nanotubes (MWCNTs) and the results revealed that 2D GN with higher surface area was a much more effective reinforcement
Compared to pure Al and 0.5 wt.% few-layered MoS2 (FLM)-Al composite powders, the 1.5 wt.% FLM-Al composite powders shown in Figure 2c, d were subjected to more severe deformation, with larger diameter and much more fractured Al powders dispersed on the surface of Al flakes

Summary

Introduction

Al matrix composites (AMCs) have attracted great attention in recent decades, and are widely used in fields including aircraft, automobile, and electronic packaging due to their high specific properties, fatigue performance, low thermal expansion coefficient, and wear coefficient [1,2,3]. In AMCs, nano-scale SiC [4], B4C [5], Al2O3 particles [6], and carbon nanomaterials including carbon nanotubes (CNTs) [7] and graphene (GN) [8,9] have been introduced into Al matrix to improve the mechanical and tribological properties of the composites. Compared to 0D and 1D nanomaterials, 2D reinforcements with high specific surface area show promising prospects due to the ensured large contact area between the reinforcements and matrix, resulting in a more effective load transfer, which is the significant strengthening mechanism in AMCs [10]. 2D GN is a promising reinforcement for enhancing AMCs. Besides, Shin [13] compared the strengthening behaviors of 2D GN with that of multi-walled carbon nanotubes (MWCNTs) and the results revealed that 2D GN with higher surface area was a much more effective reinforcement. It is of great significance to explore more possibilities of 2D nano-reinforcement with high strengthening efficiency for reinforcing AMCs

Methods

Results

Conclusion