"Friction stir welding (FSW) is a recently developed process for welding aluminum alloys that has expanded into applications other than welding by the concept of friction stir processing (FSP). Through FSP, it has been found that the properties of materials can be enhanced whether by inserting forged microstructure into a casting, consolidating regions of a part produced by powder metallurgy, or by producing materials with properties which allow them to be formed more easily to name just a few of the applications. The ability of FSP to alter the microstructure of material has lead to its expansion as a method for creating superplastic material ... This study examines the use of FSP to make commercial alloys superplastic by altering the microstructure. Not only is the understanding of the single pass process studied in more detail but the effects of using multiple passes of FSP are examined ... The use of FSP for the addition of carbon nanotubes into aluminum was also evaluated"--Abstract, leaf iv.

This book describes the fundamentals and potential applications of ‘friction stir superplasticity for unitized structures’. Conventional superplastic forming of sheets is limited to the thickness of 3 mm because the fine grained starting material is produced by rolling. Friction stir superplasticity has grown rapidly in the last decade because of the effectiveness of microstructural refinement. The thickness of the material remains almost constant, and that allows for forming of thick sheets/plates, which was not possible before. The field has reached a point where designers have opportunities to expand the extent of unitized structures, which are structures in which the traditional primary part and any supporting structures are fabricated as a single unit. With advanced optimization and material considerations, this class of structures can be lighter weight and more efficient, making them less costly, as well as mechanically less complex, reducing areas of possible failure. Discusses how friction stir processing allows selective microstructural refinement without thickness change Demonstrates how higher thickness sheets and plates can be superplastically formed Examples are presented for aluminum, magnesium and titanium alloys Covers the production of low-cost unitized structures by selectively processing cast sheets/plates

FSP is manufacturing the Technique used to modify the microstructure metals. In this process a rotating tool is penetrated in the work piece and moved in the transverse direction.Further FSP technique is used for fabrication of surface composite on aluminium substrate and homogenization of powder metallurgy aluminium alloy, metal matrix composites, and the cast aluminium alloys. By this process material properties can be improved due to enhancement of grain structure. With this technique the material have shown good corrosion resistance, high strength and high fatigue resistance.

Plates of continuously cast AA5083 were subjected to friction stir processing (FSP) by three overlapping plunge and traverses. The FSP used a threaded pin tool with a pin diameter of 3 mm, pin length of 3 mm and a shoulder diameter of 10 mm. The process was run at constant tool rotation and traverse speeds of 800 rpm and 76.2 mm min-1, respectively. The microstructure of the processed region was examined by optical microscopy and orientation imaging microscopy. FSP of the AA5083 reduced the average grain size from approximately 60 um in the base metal to 3-4 um in the processed zone. In addition, it created a homogeneous microstructure and, in particular, a refined and homogenous particle distribution without damage to the particles. Large tensile samples with gage sections of 1x3x8 mm were prepared by wire EDM for high-temperature tension testing. Tensile tests were carried out at 450 degrees C under different strain rates. The relationship between strain rate and elongation was established. A maximum superplastic elongation of ~550% was obtained at a strain rate of 3 x 10-3 s-1. The formation mechanism of refined grain structure and the superplastic characteristic of FSP material will be discussed in this paper.

This up-to-date reference text discusses the fabrication technique for strengthening of high specific strength alloys including age-hardened aluminum alloys for several industrial applications. The text presents an exhaustive overview of the materials used in the aircraft construction in general and age-hardened aluminum alloys in particular. The text discusses important concepts including surface composite fabrication using friction stir processing (FSP), FSP tools, effect of reinforcement particles, and conditions that affect strengthening during surface composite fabrication on age-hardened aluminum alloys. The text will facilitate the readers to control parameters and avoid conditions that lead to a net negative impact on the resulting composites and select the one that lead to a net gain. It will enable the readers, researchers, and professionals to plan and practice composite fabrication via FSP with a benefit of net strengthening. The understanding of specific strength of materials used in applications including aerial vehicles and manufacturing is important. The proposed text highlights importance of age-hardened alloy as one of the materials used for diverse applications. It discusses strengthening strategies of existing age-hardened aluminum alloys through composite fabrication via a solid-state FSP route. The text will help students and professionals working in the field of manufacturing, materials science, and aerospace engineering. The text discusses an important aspect of strengthening age-hardened alloy using solid-state friction stir processing for diverse applications in industries including manufacturing and aviation. It will serve as an ideal reference for graduate students, academic researchers, and professionals in the field of mechanical engineering, aerospace engineering, and materials science. It will also be helpful to the professionals working in the aviation and manufacturing industries.