Friction stir welding

POSTER TITLE Effect of Friction Stir Welding on the Corrosion Fatigue Performance of Magnesium Alloy AZ31B-H24... [Pg.12]

MICROSTRUCTURE AND MECHANICAL BEHAVIOR OF FRICTION STIR WELDED TITANIUM ALLOYS... [Pg.391]

Abstract Friction stir welding (FSW) has evolved extremely rapidly into a viable and... [Pg.391]

Key words Friction stir welding, tensile properties, titanium alloys, fatigue crack growth... [Pg.391]

The thermophysical properties of titanium alloys may also contribute to difficulty encountered during friction stir welding. Some numerical simulations of the FSW process indicate that low thermal diffusivity can contribute to the formation of advancing side wormhole or tunnel defects in friction stir welds the thermal diffusivities of titanium alloys are among the lowest of all metals. [Pg.392]

GENERAL CHARACTERISTICS OF THE FRICTION STIR WELDS OF TI ALLOYS... [Pg.392]

Alloys from all three classes, a, P, and a P, have been successfully friction stir welded at the University of South Carolina. 2 mm thick sheets of a-Ti, Ti-15V-3Sn-3Cr-3Al and Ti-6A1-4V have been FS welded at a welding speed of lOOmm/min at a tool rate of 200 rpm. The CP-Ti and the Ti 15-3-3-3 were welded using z-axis load control. Load control welding on Ti-6-4 was not stable, so that alloy was welded using position control. The P-transus temperatures for the three alloys are CP-Ti= 915°C, Ti-6-4= 995°C, and Ti-15-3-3-3= 770°C. [Pg.392]

Microstructure and mechanical behavior of friction stir welded 393... [Pg.393]

Like the other two alloys examined, the Ti-6-4 friction stir weld exhibits a highly refined weld zone microstructure and substantial overmatching in the weld zone. A crown side view of the weld is shown in figure 1(c). [Pg.393]

Transverse tensile properties of the friction stir welded samples are shown in Table 1. [Pg.395]

Table 1. Tensile properties of Ti alloy friction stir welds...

The welds of Ti-6-4 were made in displacement control rather than z-axis load control. Typically, this resulted in the formation of a small lack of penetration (LOP) defect in the weld nugget. The lack of penetration defect caused tensile failure to occur through the weld nugget. The low elongation can also be attributed to the LOP defect. Tensile properties of a second friction stir welded Ti-6-4 specimen which did not contain a LOP defect is also shown in the Table. As can be seen from this table the % elongation is much higher in this case. [Pg.396]

Bend tests were performed on friction stir welded samples and examples of the bend specimens for a-Ti and Ti-6-4 samples are shown in Figure 3. As seen here these samples could be bent without fracture. The Ti-6-4 specimen was friction stir welded at the Edison Welding Institute [2] whereas the a-Ti specimen was friction stir welded the University of South Carolina. The photograph showing the bend specimen for a-Ti is a doublepass weld in a 6.4 mm thick specimen. [Pg.396]

Figure 3. Room temperature bend tests on double pass friction stir welded a-Ti alloy (left photo) and Ti-6-4 (right photo).

It is shown here that alpha, beta and alpha-beta titanium alloys can be friction stir welded. The phase transformations that occur in the nugget region and the heat affected zone are discussed. Residual stresses were found to be quite high in the present work. Tensile properties in transverse direction were... [Pg.399]

R. L. Goetz and K. V. Jata, Modeling Friction Stir Welding of Titanium and Aluminum Alloys , in Friction Stir Welding and Processing, eds. K. V. Jata, M. W. Mahoney, R. S. Mishra, S. L. Semiatin, and D. P. Field, TMS, November 2001. [Pg.400]

A. J. Ramirez and M. C. Juhas, Microstructural Evolution in Ti-6A1-4V Friction Stir Welds , Materials Science Forum vols. 426-432 (2003) pp. 2999-3004, Trans Tech Publications, Switzerland. [Pg.400]

T.J. Lienert, W. Tang and A.P. Reynolds Microstructures, Mechanical Properties and Weldability of Friction Stir Welds on Ti Sheet Alloys , presented at Aeromat 2002, June 2002, Orlando, Florida, USA. [Pg.400]

Additional topics relating to the theme of metallic materials with high structural efficiency included phase reactions and equilibria in relevant systems (Bulanova, Ukraine), fundamental mechanisms of dynamic recovery and recrystallization (Leffers, Denmark Montheillet, France), joining by friction stir welding (Jata, USA), production of cellular metals (Sanders, USA) and... [Pg.455]

Like many new technologies, a new nomenclature is required to accurately describe observations. In FSW, new terms are necessary to adequately describe the postweld microstructures. The first attempt at classifying friction stir welded microstructures was made by Thread-gill (Ref 8). Figure 1.2 identifies the different microstructural zones existing after FSW, and a brief description of the different zones is presented. Because the preponderance of work to date uses these early definitions (with minor modifications), this reference volume continues to do so. The system divides the weld zone into distinct regions, as follows ... [Pg.2]

Fifi. 1.2 Various microstructural regions in the transverse cross section of a friction stir welded material. A, unaffected material or parent metal B, heat-affected zone C, thermomechanically affected zone D, weld nugget... [Pg.2]

Fig. 1.3 Joint configurations for friction stir welding, (a) Square butt, (b) Edge butt, (c) T-butt joint, (d) Lap joint, (e) Multiple lap joint. (f) T-lap joint, (g) Fillet joint. Source Ref 14...

B. London, M. Mahoney, B. Bingel, M. Calabrese, and D. Waldron, in Proceedings of the Third Int. Symposium on Friction Stir Welding, Sept 21-2%, 2001 (Kobe, Japan)... [Pg.5]

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