Friction stir welding of pure titanium lap joint

Abstract

The effects of welding parameters on friction stir welding of pure titanium lap joint were investigated together with the microstructural characteristics of the sound joint. Three kinds of welding defects were found under the condition of tool load control, namely, the groove-like defect, the inner cavity defect and the overheating rough surface and tool penetration defect with increasing heat input. The tool plunge depth control effectively increased the lap width compared with the tool load control, so the sound joints fractured in the base metal were acquired at 250 rev min 21 -75 mm min 21 and 200 rev min 21 -50 mm min 21 . The sound joint consisted of the thermomechanically affected zone, the stir zone, the lap zone and the top layer. The microstructure was fined obviously after welding, and finer grains were observed in the lap zone and top layer.

Influence of texture on strain localization in stir zone of friction stir welded titanium

“…Similar phenomena was also observed in FSW of pure titanium lap joints in which the optimum welding parameter range is quite narrow. The groove-like and inner cavitation defect formed at low heat input while the overheating rough surface defect was found when the high heat-input parameters were used [13,14].…”

Friction Stir-Welded Titanium Alloy Ti-6Al-4V: Microstructure, Mechanical and Fracture Properties

“…[11][12][13][14] Enabling this machine and tooling technology has so far proven to be difficult, but is currently possible at a handful of laboratories around the world. [15][16][17][18][19][20] The titanium welds and superplastic-formed joint mechanical properties reported previously [21][22][23][24][25][26][27][28][29][30][31][32] were essential for variable FSW process conditions. Since then, the process has been further developed and refined, and optimal process conditions for a given tool geometry have been identified.…”

Investigation on friction stir welding parameter design for lap joining of pure titanium

“…CP Ti plates with 2 mm in thickness were successfully friction stir butt welded at a rotation speed of 200 rpm combining with a welding speed range from 50 to 300 mm/min [2]. Very recently, CP Ti lap joints have been produced using FSW by Liu et al [7,8]. These primary studies demonstrated that the optimum welding condition for the lap joining of CP Ti plates is quite narrow.…”