Aluminum and Magnesium Metal Matrix Nanocomposites

Abstract

Lightweight materials are getting critically important for weight-saving engineering and biomedical sectors. The use of these materials is getting increasingly important for sustainable planet earth and human comfort. Aluminum and magnesium are two lightweight materials that are of paramount importance for engineers and material selectors. Efforts have been made in past few decades to evolve these two principal elements so that they can cater to a wider spectrum of applications. Composite technology utilizing micron length scale reinforcement was used actively in the past century to realize properties beyond the common alloying technique to enhance certain properties such as elastic modulus, strength, wear and damping response. With the advent of nanotechnology in the late 1990s, researchers worldwide started to use reinforcements at nano-length scale (<100 nm). The resultant nanocomposites exhibited superior combination of properties when compared to micro-composites with significantly reduced weight penalty. In view of significantly different response of elemental matrix in the presence of reinforcement at nano-length scale, it was realized by authors to put together current level of understanding of aluminum and magnesium based nanocomposites. It is hoped that this book will serve as a useful reference for students, teachers, engineers, and researchers to gain understanding of these fascinating materials.

The Effects of Fe-Particles on the Tensile Properties of Al-Si-Cu Alloys

“…In addition to this the mismatch in thermal expansion between the β-particles and the matrix phase [29]. These two effects are both originating from dispersion hardening effects [30].…”

Advanced Metal Matrix Nanocomposites

“…The end product of the DMD process is an ingot which then can be hot extruded to obtain the desired shape ( Figure 4). This process is mainly used to produce Mg nanocomposites as it circumvents the major drawbacks of stir casting namely high density of oxides in the nanocomposite, and withholding of the reinforcement particles, i.e., Al 2 O 3 , SiC, Y 2 O 3 , B 4 C, BN, ZrO 2 , ZnO, CNT, in the crucible because of density differences between the particles and the Mg alloys [3]. For instance, Srivatsan et al [38] produced an AZ31 + 1.5 vol% Al 2 O 3 nanocomposite with the alumina particles (Al 2 O 3 ) of 50 nm size.…”

“…The enhancement in the targeted property of a metallic matrix can be controlled through the selection of type, size, and the amount of reinforcement which forms the core of composite design. The research in metal-based composites gained pace primarily in 1970s when researchers attempted, stir casting, rheocasting, and powder metallurgy routes to unify metals/alloys with ceramic reinforcements [3,4] with captivating results. Improvements in mechanical properties, such as elastic modulus, creep, damping, and wear resistance, were typically reported [5,6].…”

“…To produce a fine dispersion of carbides, nitrides, and oxides in a light (non-ferrous) alloy matrix another term, reaction milling (i.e., reaction milling combines mixing and attrition with solid state reactions induced by mechanical agitation), has been used [3]; the processes control agent is not added to initiate the reaction. In this case, the milling atmosphere can be inert (or active) gases like argon, oxygen, nitrogen, or air [49].…”

Experimental Evaluation of the Coefficient of Thermal Expansion of Chilled Aluminum Alloy-Borosilicate Glass (P) Composite

“…The lower CTE of the composites can also be attributed to a proper distribution of particles within the matrix which is evident from the microstructural examinations. The variation in CTE of a MMC largely depends on its microstructure [16][17]. A uniform distribution of dispersoid within the matrix material results in a better thermal and mechanical properties, whereas, the presence of voids within the microstructure would severely hamper the thermo-mechanical properties of the metal matrix composites [18].…”