ABSTRACT
This chapter outlines the use of ball milling technique for amorphization and nanocrystallization. Nanostructuring is one of the efficient ways to reduce thermal conductivity, without much affecting the electrical properties, and is especially applied in thermoelectric materials. Ball milling is a way of producing amorphous alloys as well as nanostructured materials. It is a powder metallurgy processing technique involving cold welding, fracturing, and rewelding of powder particles in ball mill and has now become an established commercial technique to produce oxide dispersion strengthened nickeland iron-based materials. Amorphous materials can be prepared by the ball milling process starting from elements, alloys and/or compounds, and mixture of compounds and/or elements, all in powder form. The ball-milled material shows electron micrographs and diffraction images (ED) patterns with rings of very thin discrete spots verifying the polycrystalline character of material. Amorphization is the conversion of crystalline material into an amorphous one, while nanocrystallization is the incorporation of nanometer-scale structural features in a bulk matrix.
