Microstructure and mechanical properties of friction-stir-welded 6061 aluminum alloy sheets

Abstract

Vol. 53, No. 11 2003 , pp. 542-547 Microstructure and mechanical properties of friction-stir-welded 6061 aluminum alloy sheets* Shinji KUMAI**, Gosuke WAKANA***, Masato YAMAWAKI**** Kwang-Jin LEE*** and Akikazu SATO**The 6061-0 aluminum alloy sheet with two millimeter thick was welded by friction-stir-welding FSW at various welding conditions. Microstructure of the welds was investigated by optical microscopy in order to characterize the plastic flow pattern in the weld and change in size and morphology of the matrix grain structure from the original pancake-like structure in the parent sheet. The transverse cross section in the weld revealed that the boundary between the stir zone and the TMAZ thermo-mechanically-affected-zone exhibited a linear shape from the top to the bottom through the sheet thickness. An onion-ring pattern, which was common in the friction-stir-welded thick plate, was not detectable in the present stir zone. The wavy striations were observed in the transverse-and longitudinal-cross section of the weld. These were traces of the oxide films on the butt surface of the parent sheet and these provided the base for the evaluation of characteristic plastic flow in the friction-stir welded thin sheet. Yield strength and UTS of the weld were almost equivalent to those of the parent sheet. On the other hand, the reduced elongation was obtained. The weld was shown to break in the HAZ heat-affected-zone .

Aluminum friction stir welds: Review of fatigue parameter data and probabilistic fracture mechanics analysis

“…Fig. 14 shows a similar histogram and lognormal distribution for 60xx Al [114][115][116][117][118][119]8,29,28,120,121,34,9,41,50,102,122,123,44,124,46,17,125,126,48,127,112] with l = 78.7 andr = 15.5.…”

Effect of Tilt Angle and Plunge Depth of Welding Tool on Friction Stir Lap Welding of Steel Sheet and Aluminum Alloy Sheet

“…や重ね点接合 13,14) においても接合が可能なことが示されており，自動車部品への適用が進め られている 15,16) 。 FSW による異種金属接合をさらに活用するためには厚さ 1mm 以下の薄板の重ね線接合へ の適用が望まれているが，剛性低下による接合体の変形の増大 17) や熱容量低下による接合条 件の変化 18) が問題となる。FSW では，接合ツール形状と接合中の接合ツールの被接合材に対 する挿入角度(前進角)が大きく材料流動に影響することが知られている 19) 。また，鉄とア ルミの FSW による異種金属接合では， 接合界面の鉄表面に接合ツールを押し込んで新生面を 創出することが必要とされている [4][5][6][7][8][9][10][11][12] Table 1 Chemical composition of weld materials (mass%) .…”

Influence of Welding Parameters on Mechanical Properties of Friction Stir Welded 6061-T6 Launch Box

“…For the last few years, many in-depth FSW studies have been conducted about materials, welding parameters, microscopic structure, mechanical property [4][5][6][7][8][9][10][11][12] and the design of stir tools. [13][14][15][16] Comparison of the related studies indicates that differences in materials, experimental equipment and the designs of stir tools will change the relationship between operational parameters and mechanical properties.…”