Production of Al Metal Matrix Composites Reinforced With Carbon Nanotubes by Two-Stage Melt-Based HPDC-CE Method

Abstract

Carbon nanotubes (CNTs) are well known as perfect reinforcement for high strength and lightweight composites due to their high specific strength, thermal, electrical, and mechanical characteristics. One of the important challenges is to obtain a homogeneous dispersion of CNTs in metal matrix, so development technologies for producing metal matrix composites (MMCs) is of great interest. Melting followed by solidification, may be successfully utilized for synthesizing CNT-reinforced aluminum-based MMCs. In this study, Al/CNT composites have been produced by direct injection of CNTs in pure aluminum using high-pressure die casting (HPDC) method. The as-produced billets were subjected to cyclic extrusion (CE) to refine CNT agglomerates and to increase CNT dispersion in aluminum. Current investigation demonstrates that more than 50% efficiency of combined HPDC-CE production method has been achieved. The resulting composites demonstrated improved mechanical properties.

Corrosion Resistance of Al–CNT Metal Matrix Composites

“…The novel HPDC-CE method used in this research enables the manufacturing of MMCs with a significant increase in mechanical strength [14]. In the present research, it was crucial for us to demonstrate that the proposed fabrication method allows reinforcement of the material without significant degradation of corrosion resistance.…”

“…The significant contribution of the publications cited above and displayed in Table 1 is devoted to the fabrication of MMCs with additives having a fraction size from several to tens of microns. The introduction and dispersion of nano-sized additives, such as carbon nanotubes (CNTs), is a challenging issue, especially by liquid phase metallurgy [14]. However, there were attempts to fabricate aluminium-based composites with CNTs by the rolling technique [15].…”

“…It is problematic since the CNTs tend to rise to the surface without being mixed because of their poor wetting properties and great difference in their density compared with that of Al [16]. A combined two-staged method was developed to overcome these issues [14]. The authors developed a method of fabrication of metal matrix composites in which multiwall carbon nanotubes (MWCNTs) were inline dispersed in the Al matrix [14].…”

“…A combined two-staged method was developed to overcome these issues [14]. The authors developed a method of fabrication of metal matrix composites in which multiwall carbon nanotubes (MWCNTs) were inline dispersed in the Al matrix [14]. Figure 1 shows the method, which includes two main steps.…”

Powder-bed additive manufacturing for aerospace application: Techniques, metallic and metal/ceramic composite materials and trends

“…Titanium alloys provide a unique combination of physical and mechanical properties like small weight, high strength (high "strength to weight ratio"), good corrosion and fatigue resistance. Unlike carbon-based composites [60], aluminum [6] and magnesium-the Ti alloys can withstand high serving temperatures (for example aluminum usually serves up to 200°C). Excellent corrosion resistance is another factor making Ti alloys quite useful for aerospace applications.…”