Introduction NonArc Welding Processes Resistive heating chemical reactions

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Introduction Non-Arc Welding Processes • Resistive heating, chemical reactions, focused light and electrons, sound

Introduction Non-Arc Welding Processes • Resistive heating, chemical reactions, focused light and electrons, sound waves, and friction can also be used to join materials – – – – Resistance welding Oxy-Fuel Welding Friction welding (&Solid State) Laser and electron beam welding Brazing and soldering Plastics joining Adhesive bonding

Brazing (B) and Soldering (S) • In these processes, the base metals are heated

Brazing (B) and Soldering (S) • In these processes, the base metals are heated but do not melt; only the filler metal melts – Brazing filler metals having a melting point above 840° F (450°C) – Soldering filler metals have a melting point below 840°F (450°C) Brazing and Soldering

Brazing and Soldering 0. 1. 1. 2. 4. T 18. 95. 12

Brazing and Soldering 0. 1. 1. 2. 4. T 18. 95. 12

Application of Low Thermal Expansion Alloys • Thermal expansion mismatch in metalceramic joints can

Application of Low Thermal Expansion Alloys • Thermal expansion mismatch in metalceramic joints can lead to cracks in the ceramic • Thermal expansion coefficients at 25°C (10 -6 mm / mm·°C) – – Alumina, 8. 8 Nickel, 13. 3 Iron, 11. 8 Kovar, 5. 0 Kovar lid Silicon chip Alumina substrate Brazed joints 0. 1. 1. 2. 4. T 20. 95. 12

Brazing and Soldering Brazing Specifications • AWS A 5. 8 Specification for Brazing Filler

Brazing and Soldering Brazing Specifications • AWS A 5. 8 Specification for Brazing Filler Metal – 8 well-defined groups (B) plus a vacuum grade (BV) • BAg-1 • BAu-1 • BCu. P-1 (44 -46 Ag, 14 -16 Cu, 14 -18 Zn, 23 -25 Cd) (37 -38 Au, remainder Cu) (4. 8 -5. 2 P, remainder Cu) – Standard forms: strip, sheet, wire, rod, powder – Joint design tolerances, generally ~ 0. 002 - 0. 006 inches – Uses for each braze material • AWS C 3. 3 Standard Method for Evaluating the Strength of Brazed Joints

Balchin & Castner, “Health & Safety…”, Mc. Graw Hill, 1993

Balchin & Castner, “Health & Safety…”, Mc. Graw Hill, 1993

Advantages Brazing and Soldering • Joins unweldable materials – Base metals don’t melt –

Advantages Brazing and Soldering • Joins unweldable materials – Base metals don’t melt – Can be used on metals and ceramics • Joined parts can be taken apart at a later time • Batch furnace can easily process multiple parts • Portable when joining small parts

Brazing and Soldering Limitations • Joint tolerance is critical • Lower strength than a

Brazing and Soldering Limitations • Joint tolerance is critical • Lower strength than a welded joint • Large parts require large furnaces • Manual processes require skilled workers • Flux Filler metal ring surrounded by flux

NonArc Welding Processes Continued Introduction NonArc Welding ProcessesNonArc Welding Processes Continued Introduction NonArc Welding Processes
Introduction NonArc Welding Processes Resistive heating chemical reactionsIntroduction NonArc Welding Processes Resistive heating chemical reactions
RESISTIVE HEATING April 13 th 2010 RESISTIVE HEATINGRESISTIVE HEATING April 13 th 2010 RESISTIVE HEATING
RESISTIVE HEATING April 13 th 2010 RESISTIVE HEATINGRESISTIVE HEATING April 13 th 2010 RESISTIVE HEATING
Welding Jeopardy Arc Welding MIG Welding OxyAcetylene WeldingWelding Jeopardy Arc Welding MIG Welding OxyAcetylene Welding
Welding Welding Content Soldering Brazing Welding Gas weldingWelding Welding Content Soldering Brazing Welding Gas welding
OTHER PROCESSES Projection Welding Seam Welding Butt WeldingOTHER PROCESSES Projection Welding Seam Welding Butt Welding