Fasteners in Aviation

1
Introduction to Fastener Technology Part 2
An Aerospace Manufacturing Perspective
2
Fasteners in Aviation

• Fastener Overview
• Types of Fastener
• Permanent Fastening
• Welding
• Adhesive Bonding
• Riveting
• Temporary Fastening
• Threaded
• Non-Threaded

3
Permanent Fastening

• Welding
• Adhesive Bonding
• Riveting

4
Welding

• Welded Joint

5
Adhesive Bonding

• Adhesive bonded composite test strips

6
Riveting

• Rivet joints on a Cessna 152

7
Welding

• Fastening methods that join together two pieces
  of metal by melting the base metals and adding a
  filler material to form a pool of molten material
• Can be carried out by the use of heat or pressure
  or both and with or without added metal.

8
Types of Welding

• Most aerospace industry utilizes
• MIG Welding
• TIG Welding
• Friction Stir Welding (FSW)

9
MIG or GMAW Welding

• Metal Inert Gas (MIG) welding / Gas Metal Arc
  Welding (GMAW)
• Easiest welding process
• Able to bond a wide range of material types and
  thicknesses
• Easily adapted for automation and semi-automation
  welding applications

10
MIG or GMAW Welding

• Metal Inert Gas (MIG) welding / Gas Metal Arc
  Welding (GMAW) Equipment
• 1) Welding torch
• 2) Work piece
• 3) Power source
• 4) Wire feed unit
• 5) Electrode source
• 6) Shielding gas supply.

11
MIG or GMAW Welding

• Metal Inert Gas (MIG) welding / Gas Metal Arc
  Welding (GMAW) Area
• 1) Direction of travel
• 2) Contact tube
• 3) Electrode
• 4) Shielding gas
• 5) Molten weld metal
• 6) Solidified weld metal
• 7) Work piece.

12
TIG or GTAW Welding

• Tungsten Inert Gas (TIG) welding sometimes
  referred by Gas Tungsten Arc Welding (GTAW)
• Most complicated welding process
• Requires both hands to work one hand is used for
  feeding a filler metal, while the other hand is
  use to control the welding torch.
• Like GMAW, it has the ability to bond a wide
  range of material types

13
TIG or GTAW Welding

• Equipment
• A welding torch
• Constant-current welding power supply
• Shielding gas source

GTAW system setup
14
Friction Stir Welding (FSW)

• Unique solid-state welding
• Maintain the original metal characteristic
• Typically used on a large piece of metal
• Discovering a greater use in aerospace industry
  applications, such as
• Very low distortion and shrinkage
• No fumes, sparks, or porosity
• Repeatable
• Cost and weight reduction
• Improved joint quality

15
FSW process

• A. Two discrete metal work pieces butted
  together, along with the tool (with a probe).
• B. The progress of the tool through the joint,
  also showing the weld zone and the region
  affected by the tool shoulder.

16
Friction Stir Welding (FSW)

• Used to manufacture some of the Airbus component
  such as the wing rib

17
Welding Geometry

• Five basics types of weld joints are
• Butt Joint
• Lap Joint
• Corner Joint
• Edge Joint
• T-Joint

18
Adhesive Bonding

• Benefits of Adhesive bonding
• The ability to reduce significant amount of
  fasteners weight in the aerospace structures
• Improve the aerospace aerodynamic and performance
• Able to adjust rapid temperature changes, from
  sub-zero temperature in the stratosphere to
  ground-level temperatures in desert climates

19
Adhesive Bonding

• Substances that are able to bond two materials
  together by
• Adhesion
• Force between adhesive and substrate
• Cohesion
• Internal strength of adhesive itself.

20
Examples of Adhesive Bonding

• Internal structures with lightweight honeycomb
  sheets

21
Adhesive Bonding

• Adhesive bonded composite test strips with
  honeycomb core

22
Riveting

• Smooth cylindrical shaft with a head on one end
• One of the earliest methods of fastening metal
  together and most popular choices in todays
  applications for it is known as the most reliable
  fasteners
• Aerospace industries use hundreds of thousands of
  solid rivets to assemble structural parts of an
  aircraft
• Classic materials for aircraft rivets are
  aluminum, titanium, and nickel based alloys

23
Riveting

• Riveting is a primary fastening method used in
  aviation
• Much more information on riveting will follow in
  Aerospace Fastener Applications, Part 2,
  including
• Sizes and types of rivets
• Rivet part number identification
• Installation procedures