An Aerospace An Aerospace Manufacturing Manufacturing

PerspectivePerspective

Introduction to Fastener TechnologyIntroduction to Fastener Technology

Part 2Part 2

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Fasteners in AviationFasteners in Aviation

Fastener Overview:– Types of Fastener:

Permanent Fastening– Welding – Adhesive Bonding– Riveting

Temporary Fastening

– Threaded– Non-Threaded

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Permanent Fastening

Welding Adhesive Bonding

Riveting

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Welding

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•Welded Joint

Adhesive Bonding

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• Adhesive bonded composite test strips

Riveting

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• Rivet joints on a Cessna 152

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.

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Types of Welding

Most aerospace industry utilizes:– MIG Welding

– TIG Welding

– Friction Stir Welding (FSW)

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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

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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.

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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.

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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

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TIG or GTAW Welding

GTAW system setup

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

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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

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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.

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Friction Stir Welding (FSW)

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

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Welding Geometry

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

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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

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Adhesive Bonding

Substances that are able to bond two materials together by :

– Adhesion Force between adhesive

and substrate

– Cohesion Internal strength of

adhesive itself.

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Examples of Adhesive Bonding

Internal structures with lightweight honeycomb sheets

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Adhesive Bonding

21• Adhesive bonded composite test strips with honeycomb core

Riveting

Smooth cylindrical shaft with a head on one end

One of the earliest methods of fastening metal together and most popular choices in today’s 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 alloys22

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

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