Friction stir welding (FSW) is a relatively new solid-state joining process. This joining technique is energy efficient, environment friendly, and versatile. In particular, it can be used to join high-strength aerospace aluminum alloys and other metallic alloys that are hard to weld by conventional fusion welding. FSW is considered to be the most significant development in metal joining in a decade. Recently, friction stir processing (FSP) was developed for microstructural modification of metallic materials. In this review article, the current state of understanding and development of the FSW and FSP are addressed. Particular emphasis has been given to: (a) mechanisms responsible for the formation of welds and microstructural refinement, and (b) effects of FSW/FSP parameters on resultant microstructure and final mechanical properties. While the bulk of the information is related to aluminum alloys, important results are now available for other metals and alloys. At this stage, the technology diffusion has significantly outpaced the fundamental understanding of microstructural evolution and microstructure–property relationships.

/pdf/friction-stir-welding-and-processing-3hu3ejo7ub.pdf

Friction Stir Welding and Processing

The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

American Society for Testing and Materials

Using high-pressure torsion for metal processing: Fundamentals and applications

Physics and phenomenology of strain hardening: the FCC case

The current understanding of the fundamentals of recrystallization is summarized. This includes understanding the as-deformed state. Several aspects of recrystallization are described: nucleation and growth, the development of misorientation during deformation, continuous, dynamic, and geometric dynamic recrystallization, particle effects, and texture. This article is authored by the leading experts in these areas. The subjects are discussed individually and recommendations for further study are listed in the final section.

/pdf/current-issues-in-recrystallization-a-review-12181rj4pn.pdf

Current issues in recrystallization: a review

Current issues in recrystallization: A review

1.0 Introduction A. Description of Creep B. Objectives 2.0 Five-Power-Law Creep A. Macroscopic Relationships B. Microstructural Observations C. Rate-Controlling Mechanisms D. Other Effects on Five-Power-Law Creep 3.0 Diffusional Creep 4.0 Harper Dorn Creep A. The Size Effect B. The Effect of Impurities 5.0 Three-Power-Law Viscous Glide Creep 6.0. Superplasticity A. Introduction B. Characteristics of Fine Structure Superplasticity C. Microstructure of Fine Structure Superplastic Materials D. Texture Studies in Superplasticity E. High Strain Rate Superplasticity (HSRS) F. Superplasticity in Nano and Submicrocrystalline Materials 7.0 Recrystallization A. Introduction B. Discontinuous Dynamic Recrystallization (DRX) C. Geometric Dynamic Recrystallization D. Particle Stimulated Nucleation (PSN) E. Continuous Reactions 8.0 Creep Behavior of Particle Strengthened Alloys A. Introduction and Theory B. Small Volume Fraction Particles That Are Coherent and Incoherent with Small Aspect Ratios 9.0 Creep of Intermetallics A. Introduction B. Titanium Aluminides C. Iron Aluminides D. Nickel Aluminides 10.0 Creep Fracture A. Background B. Cavity Nucleation C. Growth

Michael E. Kassner

Papers

Current issues in recrystallization: a review

Current issues in recrystallization: A review

Fundamentals of Creep in Metals and Alloys

Creep cavitation in metals

Five-power-law creep in single phase metals and alloys