What is the process for Adhesive Bonding?
- Clean highest level of contamination
- Remove Oxide Layer
- Apply Adhesive
- Apply Mechanical Pressure
What kind of adhesive can bond metals together?
Acrylic adhesives
Joint strength depends on the joint design, but bonding strength can be as high as 4000 PSI.
What are some of the advantages of Adhesive Bonding over Welding?
- Eliminates the finish step in welding
- Good for bonding thin metals.
- Can be applied for difficult to weld areas.
- Good for where high temperature is a concern.
- Applications with difficult to reach joints.
What are some applications of Adhesive Bonding?
- Securing a bracket to a metal tank.
- Repairing leak on a tank
- Attaching a ladder to a tank
- Appliances
- Electronics
Why should you remove the oxide layer from aluminum before welding?
Aluminum oxide on the surface of the material melts at 3,700 F while the base-material aluminum underneath will melt at 1,200 F. Therefore, the oxide on the surface of the base material will prevent penetration of the filler metal into the workpiece.
What are some differences between welding aluminum and steel?
- Aluminum should be “hot and fast”
- With aluminum you should push rather than pull
- The oxide layer needs to be removed
- Melting point of aluminum is much lower
What are the only aluminum alloys that can be welded in the 7xxx and 2xxx series?
7003 & 7004 - often seen as extrusions
7039 - often seen as sheet or plate
Examples: Bike Frame, Base ball Bat
What is the problem with welding 6xxx series aluminum and how is it resolved?
They are crack-senstive and require the correct weld filler metal.
What is Soldering?
it is a process in which two metals are joined together by melting and putting a filler metal (solder) into the joint, and the filler metal has a lower melting point than the adjoing metal.
When is Aluminum Soldering used?
When aluminum needs to be bonded to copper.
Ex: heat sink, sensors, electronics, and electrical power.
How does soldering differ from welding?
The soldering does not involve melting the work piece like welding does.
What is Brazing?
is a metal-joining process in which two or more metal items are joined together by melting and flowing a filler metalinto the joint, the filler metal having a lower melting point than the adjoining metal.
How does Brazing compare to Welding and Soldering?
It does not metal the work piece like welding, but still has higher temperatures than soldering.
What are the advantages of Brazing?
- It can be automated because of the individual process paramteres are less sensitive to variation
- It produces a clean joint without the need for secondary finishing.
- Less thermal distortion.
What are some disadvantages of Brazing?
- Lack of Strength
- Asthetic disadvantage, joint is usually a differnt color
- Can be damaged under high service temperatures
