The American University in Cairo Mechanical Engineering Department MENG 433: Welding/Casting Design & Inspection A Presentation for Free! Friction Stir Welding Mechanical Properties & Microstructure Presented by Moataz M. Attallah Presented to Dr. Hanadi SalemMENG 433 Class

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results ConclusionOutline  Welding: Definition, types, nomenclature  Aluminum Welding: types, problems associated with  Friction Stir Welding: Definition, applications, parameters, welding quality

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results ConclusionWelding Definition A localized coalescence of metals or non- metals produced either by heating the materials to the welding temperature, with or without the application of pressure, or by the application of pressure alone, with or without the use of a filler material. (Davies, 1990)

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion Welding Categories (1) Fusion welding ●The heat for fusion/melting is supplied by an electric/chemical/other energy sources. ● Filler material may/may not be used. Laser welding Electric arc welding Oxyacetylene

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion Welding Categories (2) Solid state welding  Pressure and heat (supplied from friction or electric resistance) are involved.  No filler material.  Full melting is not required (softening). Seam welding Spot welding Friction welding

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion Evaluation of Welds Weldability:  Preservation of mechanical properties.  Absence of inclusions.  Produce crack free welds.  Undesirable-post weld microstructure.  Minimal reactivity with the atmosphere in service.

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion Aluminum Alloys Welding  Al-Cu (2xxx) series is extensively used in aerospace and transportation applications  High risk of cracking/oxidation during welding

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion Existing Technologies TIG/MIG/MAG Metal/Tungsten Inert/Active Gas Welding

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion Series 2xxx Weld Defects Porosity Cracks Liquation cracking

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion New Technology Friction Stir Welding (FSW)  Invented by the Welding Institute (TWI) UK in late  Solid-state welding technique suitable for difficult-to-weld materials.  No filler (electrode) required.  Showed success with variety of alloys.  Suitability for Al 2xxx series is under investigation.

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion FSW Process Description

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion FSW Process

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion Welding Tool Tool Steel Whorl TM Tool

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion Process Capabilities Large Thickness Various joint geometries Long sheetsHigh weld quality

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion Process Advantages  Low distortion/shrinkage, even in long welds  Excellent mechanical properties as proven by fatigue, tensile and bend tests  No fume  No porosity  Energy efficient  Non-consumable tool (no filler wire)  No gas shielding for welding aluminum  Used in transportation industry

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion Process Limitations  Not enough data has been published for process control and quality for 2xxx Al  Feasible for welding of plates and sheets (no other possible sections)

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion Process Parameters Vertical Force (N) Speed (RPM) Feed rate mm/sec

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion Weld Quality FS Weld Weld Nugget (Cross-section) A. Unaffected material (base metal) B. Heat affected zone (HAZ) C. Thermo-mechanically affected zone (TMAZ) D. Weld nugget/Stirred zone

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results Conclusion Initial Results

Introduction Welding Al. Welding FSW Tool Capabilities Adv/Lim/Par.AdvLimPar. Initial Results ConclusionConclusions  FSW is a novel welding technique, yet without enough experimental data.  The process can be considered promising in welding Al 2xxx alloys.  More data will be available (hopefully) by the end of the current study.

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