Processing, Microstructures, and Mechanical Properties of Magnesium Matrix Composites: A Review

Abstract

In the last two decades, lightweight magnesium matrix composites have been the hot issue of material field due to their excellent mechanical and physical properties, e.g., high-specific strength and modulus, good wear resistance, and damping capacity. As compared with aluminum matrix composites, magnesium matrix composites have merit in their specific weight and have wide applications in aerospace and aeronautical fields. Generally, the processing techniques for magnesium matrix composites can be categorized as conventional and special processing routes. In recent years, as a special processing route, metal melt infiltration into porous ceramic preform featured by its low cost and availability of high-volume fraction of reinforced ceramics have been receiving much attention. Thus, in this review, one emphasis was put on the description of this processing technique in association with the means to obtain good wettability, the prerequisite for this kind of processing method. Based on the recognized fact that there exist clean interface and bonding ability between ceramics and matrix metal, in-situ reaction synthesis is usually utilized to fabricate magnesium matrix composites. Therefore, the interfacial feature was also reviewed for the in-situ reaction synthesis. Characterizations of microstructures and various mechanical-physical properties were finally summarized for magnesium matrix composites including tensile response, wear resistance, creep behavior, and damping capacity.

Mechanical Properties of Thixoforged In Situ Mg2Sip/AM60B Composite at Elevated Temperatures

“…Combining the mechanical properties of magnesium alloys with ceramics, magnesium-based composites exhibit a higher service temperature with affordable cost [9][10][11][12]. Therefore, the magnesiumbased composites become attractive candidates for the applications at elevated temperatures [13].…”

Characterisation of Microstructure of We43 Magnesium Matrix Composites Reinforced with Carbon Fibres

“…Nevertheless, magnesium alloys are characterised by good damping capacity, excellent castability (suitable also for high-pressure die-casting) and weldability under controlled atmosphere. Moreover, this group of materials exhibits better mechanical properties, electrical and thermal conductivity and resistance to ageing in comparison with plastics [1,[3][4][5]. Mentioned properties enable the application of magnesium alloys in many industries, but the major drawbacks, limiting the extensive usage of these alloys, are relatively poor corrosion resistance and insufficient mechanical properties at elevated temperatures.…”

“…For broadening its application it is of particular interest to use processing problems coatings (copper, nickel, silicon carbide or titanium boride) and thermal treatments (the annealing of fibres to eliminate gases adsorbed on the surface of reinforcement) are applied. It provides the decrease of the contact angle and in consequence -improvement of wettability [2][3][4][5][10][11][12].…”

“…The methods could be divided into two main groups -conventional and special. Four well established processing methods -stir casting, squeeze casting, powder metallurgy and liquid metal infiltration are considered as conventional methods, while pressure infiltration, in-situ reaction synthesis, mechanical alloying and spray forming are known as special methods [3,5,9,13].…”

“…This kind of material combines the metallic properties of magnesium (low density, ductility and damping capacity) with ceramic characteristic (high strength, wear resistance), leading to greater strength and higher service temperature capabilities [3,9]. For instance, the magnesium matrix composite unidirectionally reinforced with continuous carbon fibre can readily show a bending strength of 1000 MPa with a density as low as 1,8 g/cm 3 to the temperature of up to 350-400°C [5]. To ensure certain properties fibre and particle reinforcements are used.…”