In Situ Synchrotron Radiation Diffraction Study of Compression of AZ91 Composites Reinforced with Recycled Carbon Fibres

Abstract

Lightweight structural materials are increasingly sought after in the automotive and aerospace industries for their potential to improve fuel efficiency. Magnesium-based metal-matrix composites are potential candidates for these kinds of applications. The use of recycled carbon fibres offers further energy and cost savings. The recycled carbon fibre composites were manufactured by stir casting with high-dispersion shearing, then were extruded and subsequently heat treated. The compressive deformation mechanisms of the composites compared to AZ91 were investigated using in situ synchrotron radiation diffraction. An increase in ultimate compressive strength was achieved in the composites compared to AZ91. The deformation mechanisms active in the composites were similar to those in AZ91. Magnesium alloys in compression typically show extensive twinning; this was observed in AZ91 and the AZ91 composites. The stress required for twinning onset was increased in the composites, and the twin volume fraction at failure was decreased compared to AZ91.

Relationships between Processing and Properties of Magnesium-Based Alloys

“…Eight research articles have been published in this Special Issue of Crystals. The different alloy systems, Mg-Ca-Zn [1][2][3], Mg-Zn [4], Mg-Al-Zn-Mn [5,6], Mg-Dy-Nd-Zn-Zr [7], and Mg-Gd-Mn [8], were investigated, and the following production processes were used: extrusion [1,3,5,6,8], ECAP [2], turn-induced deformation (TID) [3], rolling [4,5], and heat treatment [5][6][7].…”

“…The next contribution considered the possibilities of developing Mg metal matrix composites. In order to recycle Carbon Fibres (rCF) into Mg hybrid material, Mg-9Al-1Zn-0.2 Mn (wt%, AZ91) with 5 wt.% and without rCF was cast, heat treated, and extruded + heat treatments (T4 and T6) by Mance et al [6]. The reinforcements with 100 µm and 500 µm long rCF achieved a 32 and 41 MPa increase in UCS, respectively, compared to AZ91.…”