Friction stir processing (FSP), developed based on the basic principles of friction stir welding (FSW), a solid-state joining process originally developed for aluminum alloys, is an emerging metalworking technique that can provide localized modification and control of microstructures in near-surface layers of processed metallic components. The FSP causes intense plastic deformation, material mixing, and thermal exposure, resulting in significant microstructural refinement, densification, and homogeneity of the processed zone. The FSP technique has been successfully used for producing the fine-grained structure and surface composite, modifying the microstructure of materials, and synthesizing the composite and intermetallic compound in situ. In this review article, the current state of the understanding and development of FSP is addressed.

Friction stir processing technology: A review

Effect of rotational speed and probe profile on microstructure and hardness of AZ31/Al2O3 nanocomposites fabricated by friction stir processing

http://english.imr.cas.cn/research/researchprogress/201412/W020141209386112215608.pdf

Enhanced mechanical properties of Mg–Al–Zn cast alloy via friction stir processing

Friction stir welding (FSW), a highly efficient solid-state joining technique, has been termed as “green” technology due to its energy efficiency and environment friendliness. It is an enabling technology for joining metallic materials, in particular lightweight high-strength aluminum and magnesium alloys which were classified as unweldable by traditional fusion welding. It is thus considered to be the most significant development in the area of material joining over the past two decades. Friction stir processing (FSP) was later developed based on the basic principles of FSW. FSP has been proven to be an effective and versatile metal-working technique for modifying and fabricating metallic materials. FSW/FSP of aluminum alloys has prompted considerable scientific and technological interest since it has a potential for revolutionizing the manufacturing process in the aerospace, defense, marine, automotive, and railway industries. To promote widespread applications of FSW/FSP technology and ensure t...

Recent Advances in Friction Stir Welding/Processing of Aluminum Alloys: Microstructural Evolution and Mechanical Properties

Microstructural refinement and property enhancement of cast light alloys via friction stir processing

Friction stir processing (FSP) has been applied to cast aluminum alloy A356 plates to enhance the mechanical properties through microstructural refinement and homogenization. The effect of tool geometry and FSP parameters on resultant microstructure and mechanical properties was investigated. The FSP broke up and dispersed the coarse acicular Si particles creating a uniform distribution of Si particles in the aluminum matrix with significant microstructural refinement. Further, FSP healed the casting porosity. These microstructural changes led to a significant improvement in both strength and ductility. Higher tool rotation rate was the most effective parameter to refine coarse Si particles, heal the casting porosity, and consequently increase strength. The effect of tool geometry was complicated and no systematic trend was observed. For a standard pin design, maximum strength was achieved at a tool rotation rate of 900 rpm and traverse speed of 203 mm/min. Post-FSP aging increased strength for materials processed at higher tool rotation rates of 700 to 1100 rpm, but exerted only a marginal effect on samples prepared at the lower rotation rate of 300 rpm. Two-pass FSP with 100 pct overlapping passes resulted in higher strength for both as-FSP and post-FSP aged conditions.

S. R. Sharma

Papers

Microstructural modification of as-cast Al-Si-Mg alloy by friction stir processing