The main objective of publishing this book has been to give an idea of nanocomposite materials. A sincere effort has been made to give a clear understanding of the concepts of various synthesis methods of nanomaterials, their characterization techniques, various fabrication techniques of nanocomposite materials, and mechanical testing methods of nanocomposite materials. The book is meant to be useful to enthusiastic researchers in mechanical engineering and material science as well as those who want to do innovative projects in post-graduation and under graduation level also. The parameters kept in mind while writing the book are the coverage of contents, prerequisite knowledge of students, lucidity of writing, clarity of diagrams and the variety of optimization, and simulation problems.This book is organized into eight numbers of chapters. Chapter 1 elaborates on the background and need of this work and the necessity for aluminium-based nanocomposites along with their applications. Chapter 2 presents a literature review that includes nanomaterial preparation methods, fabrication of metal matrix composites, characterization of composites, and optimization techniques. Chapter 3 elaborates state of art devices and instruments used to prepare nanomaterials, characterization of nanomaterials, fabrication of metal matrix nanocomposites, and for testing the mechanical behavior of nanocomposites. Chapter 4 elaborates on the synthesis of nano rice hush ash using planetary ball milling and optimization of various milling parameters. Chapter 5 details the characterization of nanoparticles using particle size analyzer, XRD, SEM, Raman spectroscopy, and TG-DTA. Chapter 6 details the fabrication of nanocomposites and microstructural studies. The casting parameters such as stirring speed, diameter of the impeller, and the position of the impeller in the crucible were optimized using CFD techniques. Chapter 7 describes the mechanical characterization of nano metal matric composites. Micro-hardness, tensile strength, and fracture morphology are presented in detail. Chapter 8 deals with the optimization of casting parameters such as the temperature of the furnace, stirring speed, and stirring time to get better hardness and tensile strength of the fabricated nanocomposites of different weight mixes of reinforcement. Chapter 9 concludes the activities and provides the gist of all the findings of the work.