Other Aluminum Welding Processes

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ther Aluminum Welding Process

description

Other Aluminum Welding Processes. Resistance Welding. Learning Activities View Slides; Read Notes, Listen to lecture Do on-line workbook. Lesson Objectives When you finish this lesson you will understand:. Keywords. Weld Bonding. - PowerPoint PPT Presentation

Transcript of Other Aluminum Welding Processes

Page 1: Other Aluminum Welding Processes

Other Aluminum Welding Processes

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Resistance Welding

Lesson ObjectivesWhen you finish this lesson you will understand:•

Learning Activities1. View Slides; 2. Read Notes, 3. Listen to lecture4. Do on-line workbook

Keywords

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Weld Bonding

Messler, R, “Joining of Advanced Materials” Butterworth-Heinemann, 1993

Adhesives are Epoxy, modified-epoxy, or elastomeric urethane adhesives, sometimes with fillers.

When conductive metal fillers are used, welding parameters are nearly the same as those used for welding without adhesives

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Weld Bonding

Advantages• Increased static tensile and/or shear strength• Increased fatigue life• Gas tight or fluid tight bonds• Improved corrosion resistance• Complete interface bonding for load transfer

Disadvantages• High percent of irregular shaped nuggets• Higher percentage of expulsion

Alternate Process• Weld then back-infiltrate with low-viscosity adhesive

Messler, R, “Joining of Advanced Materials” Butterworth-Heinemann, 1993

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McCleary, S & Hulting, F, “Weldbonding of Aluminum Automotive Body Sheet”, SAE Paper 950715, 1995

Variables That Can Effect Weld Bond Quality• Aluminum Alloy Type• Type of Adhesive• Presence of a Forming Lubricant• Metal Surface Treatment

Effect on• Weld Current (Heat) Required to Produce Weld• Strength of Weld

Weld Bonding

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McCleary, S & Hulting, F, “Weldbonding of Aluminum Automotive Body Sheet”, SAE Paper 950715, 1995

Higher Bulk Resistance

Lower SurfaceResistanceLower Adhesive Resistance

Oil Film HigherResistance

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Roll Spot & Seam Welding Aluminum

• Higher Current than Steel - lower resistance, shunting• Excessive travel speed can result in Al pick-up on wheel - Increase time between welds, reduce travel speed• Radius face wheel - face radii 1-10 inch• Clean wheels:

• After every 3-5 revolutions - continuous• After eve4y 10-20 revolution - Roll Spot welding• Or continuous cleaning

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AWS Welding Handbook, Vol 3, 1996

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Capacitor Discharge Stud Welding of Aluminum

• Use AC to charge capacitors• Three Processes

• Drawn Arc (inert gas shield)• Initial Contact• Initial Gap(preferred)

• Two Ground Clams for even Current Distribution

AWS Welding Handbook

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Capacitor Discharge Stud Welding of Aluminum

• Studs commonly made of Al-Mg Alloys (high strength good ductility)• Base metal 1100, 3000 & 5000 series low copper 7000 series

AWS Welding Handbook

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AWS Welding Handbook

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AWS Welding Handbook

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AWS Welding Handbook

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Flash Welding of Aluminum

• Equipment similar to that used for steel• More rapid platen motion than for steel - softer material• Higher currents - less resistance• Electrodes fabricated from tool steel to prevent sticking