Abstract
In the present paper, tool wear and the rate of wear during friction stir welding (FSW) of Ti-6Al-4V alloy are investigated. A conical tungsten carbide tool was used to produce butt-type friction stir welded joints in two-millimeter thick Ti-6Al-4V sheets. An original design of a movable pin allowed for the examination of the tool damage for each process condition. The influence of tool degradation on the quality of the welded joints and the damage brought to the microstructure are examined and discussed. For this purpose, optical and scanning electron microscopies as well as EDX analyses were used to examine the tool wear and the resulting macrostructures and microstructures. The type and nature of the defects are also analyzed as a function of FSW processing parameters. Important geometry and weight variations were observed on the pin and shoulder for all welding conditions, in particular when low tool rotation and travel speeds were used. Experimental results also show that the radial wear of the pin is not uniform, indicating the presence of important frictional temperature gradients through the thickness of the joint. The maximum wear was measured at a location of about one millimeter from the pin root center. Finally, tool rotation was determined as the most significant process parameter influencing both tool wear and microstructure of the joints.
Highlights
Manufacturing of structural components made of welded Ti-alloy sheets or thin plates is continuously increasing in the transportation and energy industries mainly because these alloys possess an excellent combination of low-density, superior mechanical properties along with high corrosion and erosion resistance
Friction stir welding (FSW) as a solid state welding process is one of the most promising techniques for joining sheets and thin plates made of titanium alloys, avoiding a large number of difficulties arising from the use of fusion welding processes, and could be used for the manufacturing of large size components for aerospace applications [3,4,5,6]
Examination of weld cross-sections shows shows the presence of three distinct zones for all process conditions: Base Metal (BM), Heat Affected the presence of and threeStirred distinct zones forThe all process conditions: Base Metal
Summary
Manufacturing of structural components made of welded Ti-alloy sheets or thin plates is continuously increasing in the transportation and energy industries mainly because these alloys possess an excellent combination of low-density, superior mechanical properties along with high corrosion and erosion resistance Fusion welding techniques such as tungsten inert gas (TIG) or laser are extensively used to join titanium alloys. Park et al and Yutaka et al [17,18] conducted a detailed study on the tool wear in FSW stainless and ferritic steel welds using pcBN and Co tools, respectively They reported that Cr-rich borides were formed at the interface between the workpiece and the pcBN tool, resulting in significant mechanical/chemical wear. On the basis of the obtained results, the process conditions leading to optimum weld quality are determined
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
