CNT-Reinforced Metal Matrix Composites: A Review

Materials have been an important part of human life from its very existence. Especially metals have played a vital role in the development of human kind. From tools to utensils, metals have been used extensively. In today’s scenario, pure metals and metal alloys have become a bit less popular as compared to metal matrix composites (MMCs). This has happened because of the extraordinary properties possessed by MMCs. Properties such as high compressive and yield strength, good creep and wear resistance, good fatigue and corrosion resistance, ability to withstand high temperatures, high thermal conductivity and low coefficient of thermal expansion make MMCs suitable for most demanding applications such as aerospace, defense, surgical, automobile, structural and thermal management applications. MMCs have gained popularity over the years due to above-mentioned properties which distinguish them from pure metals and traditional alloys which possess very few of them taken together. There are several ways for the synthesis of MMCs such as sintering, powder metallurgy (P/M), squeeze casting, liquid infiltration and stir casting. This paper presents the latest developments in the field of metal matrix composites reinforced with carbon nanotubes (CNTs) including synthesis and applications. Some of the classical papers from the past have also been included to present a comprehensive picture as far as microstructure and alignment of CNT within the metal matrix is concerned. The paper indicates toward the challenges in the processing of CNT-reinforced MMCs and also points toward the potential future applications of these materials in the future.