ME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 1 Joining ver. 1ME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 2 Overview • Welding using interfacial shear • Adhesive bonding • Soldering and brazingME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 3 Ultrasonic Welding Plastic Metal Anvil Horn Materials being weldedME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 4 Friction WeldingME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 5 Friction Welding MachineME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 6 Friction welding processFriction Welding Process ME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 7ME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 8 Friction welded drive shaftME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 9 Friction stir welding • used for aluminum • requires no filler • low distortion • low microstructural changes • probe – 5-6 mm diameter – 5 mm height • temps – 230 – 260oCME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 10 Friction Stir WeldingME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 11 Friction Stir Welding FSW Normal weldME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 12 Friction Stir Welded PartME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 13 2R 2r Adhesive Bonding • thinner is better – tri-axial state of stress - “contact strengthening” • any thin film will bondME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 14 Adhesive Guidelines • For large bond areas – low viscosity to form joint quickly – high viscosity (surface tension) for strength • High force for long timesME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 15 Adhesive Types • Hot melt adhesive – thermoplastic material • Evaporate volatile – release solvent or carrier • Polymerize in situ – cyanoacrylate (super glue), epoxy • Pressure sensitive – masking tapeME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 16 Mechanical Interlocking Bonding • Depends on bulk strength of adhesive. adherend adhesive adherendME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 17 Choice of Adhesive Bond Type • Rough surface – mechanical interlocking – need adhesive with good bulk properties • Smooth surface – surface tension – need to prepare surface more carefullyME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 18 Joint DesignME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 19 Long Term Performance • Environmental degradation • Moisture is nastyME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 20 Soldering and Brazing • Typically, a liquid metal joins two solid surfaces. • Solder T < 425oC • Braze T > 425oCME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 21 Pipe Solder JointME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 22 Circuit BoardsME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 23 Intel Mini-cartridgeBumps and Alignment ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2011 24 Misaligned AlignedME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 25 Solder TapeME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 26 Soldering Uses • Join dissimilar materials • Electronics • Microelectronics • Pipes • Repairing jewelryME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 27 Brazing Uses • Join dissimilar materials – repairing metal parts – ceramics and glasses to other materialsME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 28 • A - flux over oxidized metal • B - boiling flux removes oxide • C - base metal in contact with molten flux • D - molten solder displaces molten flux • E - solder alloys with base metal • F - solder solidifiesME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 29 Wave Soldering Schematic direction of travel chip leads circuit board solder wave solder jointME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 30 Wave Soldering MachineME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 31 Flux ApplicationME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 32 Solder Wave WaveME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 33 Flip Chip / Ball Grid Arrays / Surface Mount TechnologyME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 34 Solder and Braze Materials • Tin • Lead • Antimony • Silver • Copper • Phosphorous • Cadmium • Gold • Iron • Chrome • Nickel • Silicon • Zinc • ManganeseME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 35 Brazing materials • Aluminum-silicon for aluminum alloys – 570 – 620oC • Gold for iron, nickel alloysME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 36 Flux • To prevent oxidation. • Used to clean off surface contaminants. • Proper flux needed to decompose surface oxides. • Clean surfaces are needed for good wetting and bonding. • High temperatures increase cleaning and speed of process.ME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 37 Flux • Molten metals have very high surface tensions. • Fluxes must have lower surface tensions, so they can be displaced by solder. • Solders are usually metals. • Fluxes can be organic or inorganic. – e.g. boric acid, fluorides/chloridesME 4210: Manufacturing Processes and Engineering Prof. J.S. Colton © GIT 2011 38 Joint Strength • Solder: – Controlled by creep of solder • Solder rule of thumb: – Don’t exceed 1,000 psi above 0.75 Tmelting (absolute) • Brazing – strengths up to 5,000 to 10,000 psiME 4210: Manufacturing Processes and