1. BRAZING, SOLDERING, AND ADHESIVE BONDING (Chapter 31)

2. Brazing, Soldering, and Adhesive Bonding
Chapter Overview
This chapter considers three joining processes that are similar to welding in certain respects:
Brazing, Soldering, and Adhesive Bonding
Brazing
Brazed Joints
Filler Metals and Fluxes
Brazing Methods
Soldering
Joint Designs in Soldering
Solders and Fluxes
Soldering Methods
Adhesive Bonding
Joint Design
Adhesive Types
Adhesive Application Technology
Advantages and Disadvantages of Each Process

3. Brazing
Is a joining process in which a filler metal is melted and distributed by capillary action between the faying surfaces of the metal parts being joined
No melting of the base metal occurs
Only the filler melts
Filler metal (brazing metal) has a melting temperature above 450° C but below the melting point of the base metal to be joined

4. Brazed Joints Two common types: butt and lap joints
Been adapted for the brazing process
Lap joints more widely used since they provide large interface between parts
Clearance between mating surfaces of base parts is important as must be large enough as not to restrict molten filler metal
Typical brazing clearances at brazing temperature is mm
Cleanliness of the joint surface prior to brazing is important – must be free of oxides, oils, & other contaminants to promote wetting & capillary attraction

5. Filler Metals and Fluxes
Common filler metals: aluminum silicon, copper, copper and phosphorous, copper & zinc, gold & silver, nickel alloys, silver alloys
Qualifications for brazing metals
Melting temperature must be compatible with base metal
Surface tension in liquid phase must be low for good wettability
Fluidity of molten metal must be high for penetration into the joint
Chemical and physical interactions with the base metal must be avoided
The metal must be capable of being brazed into a joint of adequate strength for the application

6. Brazing Methods Torch Brazing gfdsdfgfd Furnace Brazing fdsasdfda
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Induction Brazing
Resistance Brazing

7. Brazing Methods Cont’d
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Dip Brazing
Infrared Brazing
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Braze Welding

8. Advantages & Disadvantages

9. Soldering
Similar to braising and can be defined as a joining process which a filler metal with a melting point below 450° C is melted and distributed by capillary action between the faying surfaces of the metal parts to be joined
No melting of base metal occurs
Filler metal wets and combines with base metal to form a metallurgical bond
Filler metal is called solder

10. Joint Designs in Soldering

11. Solders & Fluxes

12. Soldering Methods
Hand Soldering
Wave Soldering
Reflow Soldering

13. Advantages & Disadvantages

14. Adhesive Bonding

15. Joint Design

16. Adhesive Types Natural Adhesives Inorganic Adhesives
Synthetic Adhesives

17. Adhesive Application Technology
Surface Preparation
Application Methods:
Brushing
Flowing
Manual rollers
Silk screening
Spraying
Automatic applicators
Roll coating

18. Advantages & Disadvantages

19. References
Groover, M. P. (2010). Fundamentals of modern manufacturing: materials, processes, and systems. Upper Saddle River, N.J.: Prentice Hall.