• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

Card Range To Study



Play button


Play button




Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

80 Cards in this Set

  • Front
  • Back

What are the two most important factors in preventing corrosion?

1. Removal of the electrolyte

2. Application of protective coating

What is the electrochemical deterioration of a material or its properties due to its chemical reaction with the surrounding environment?


What is the smallest unit made up of an element, made up of a positively charged nucleus surrounded by a system of negatively charged electrons?


What is a negatively charged subatomic particle?


What is an atom or group of atoms or molecules which has acquired a net electric charge by gaining or losing electrons?


What is a liquid containing ions?


All metals will corrode to some extent in a natural environment.

Theory of Corrosion

What four conditions must exist before metal corrosion can occur?

1. Anode (metal with tendency to corrode)

2. Cathode (dissimilar conductive material)

3. Electrolyte (conductive liquid)

4. Electrical contact

Where do all corrosive attacks begin?

On the surface of the metal

When is the best time to prevent corrosion?

Design stage

Most alloys are made up entirely of small crystalline regions called _____.


The _____ the difference in dissimilar metals, the _____ corrosion occurs.

Greater, difference

If the surface area of the _____ (corroding metal) is smaller than the surface area of the _____ (less active metal), corrosion will be rapid and severe.

Anode, cathode

What occurs when the concentration of the electrolyte on the surface varies from one location to another?

Concentration Cell

What occurs when some of the electrolyte on a metal surface is partially confined, metal in the confined area corrodes more rapidly than other metal surface areas?

Oxygen Concentration Cell

What environments tend to produce more rapid corrosion due to accelerated chemical reactions?

Higher temperature

What is the most common type of corrosion that results from a direct chemical attack on a metal surface that proceeds over the entire exposed surface?

Uniform Surface Corrosion

What two appearances does uniform surface corrosion have?

1. Dulling or etching of surface.

2. Rough and possibly frosted.

What two ways can you treat uniform surface corrosion?

1. Coating/sealing

2. Air movement and drain holes

What corrosion occurs when different metals are in contact with each other and an electrolyte, such as seat water?

Galvanic Corrosion

What appearance does galvanic corrosion have?

Corrosion at the joint between metals

When is the potential for galvanic corrosion the greatest?

When two metals are well separated from each other on the galvanic series.

What corrosion occurs when the form of extremely localized attacks results in holes in the metal?

Pitting Corrosion

What appearance does pitting corrosion have?

White or gray powdery deposits, similar to dust.

What metal is most susceptible to pitting?

Stainless steel

What corrosion is the attack on the grain boundaries of the metal?

Intergranular Corrosion

What type of corrosion are aluminum alloys highly susceptible to?

Intergranular Corrosion

What is the advanced form of intergranular corrosion where the surface grains of a metal are lifted up by the force of expanding corrosion products occurring at the grain boundaries?

Exfoliation Corrosion

What appearance does exfoliation corrosion have?

Lifting up or swelling

How do you prevent exfoliation corrosion in aluminum sheet around steel fasteners?

Separate the aluminum and steel by a barrier

What corrosion occurs when in any crevice where a stagnant solution has pooled?

Crevice Corrosion

What three methods are used to close crevices in order to prevent crevice corrosion?

1. Welding

2. Soldering

3. Nonabsorbent gaskets

What is a form of crevice corrosion which occurs on metal surfaces having a thin organic protective coating?

Filiform Corrosion

What corrosion is recognized by its characteristic worm-like trace of corrosion products beneath the coating?

Filiform Corrosion

What four ways can filiform corrosion be prevented?

1. Keep humidity below 65%

2. Using coating with low rate of diffusion of oxygen and water vapors

3. Maintaining coatings

4. Applying CPC (corrosion preventive compounds)

What is the increase in the rate of attack on a metal due to the action of a corrosive fluid against the metal surface?

Erosion Corrosion

What is erosion corrosion characterized by?

Grooves, gullies, waves, rounded holes and/or valleys in the metal surface

What is the intergranular or transgranular cracking of a metal caused by the combined effects of constant tensile stress and corrosion?

Stress Corrosion (also called Stress Corrosion Cracking SCC)

What type of corrosion is an extremely dangerous type of failure because it can occur without warning?

Stress Corrosion (also called Stress Corrosion Cracking SCC)

What three specific environmental effects have been identified which cause stress corrosion cracking?

1. Salt solutions

2. Sea water

3. Moist salt laden air

What three ways can stress corrosion be prevented?

1. Insulating barrier

2. Protective coatings

3. Water dispalcing corrosion preventive compunds

What is the cracking of metals caused by the combined effects of cyclic stress and corrosion?

Corrosion Fatigue

What three measures are used to prevent corrosion fatigue?

1. Reduce stress

2. Use corrosion inhibitors

3. Apply metallic coating

What corrosion occurs at the contact areas between materials under load subject to repeated vibration?

Fretting Corrosion

What general appearance does fretting corrosion have?


What corrosion occurs at high temperatures, such as those found in turbine engine combustors, turbine sections, and afterburners?

Hot Corrosion

What can reduce hot corrosion?

High temperature ceramic coatings

What are the most widely used materials for aircraft construction?

Aluminum and aluminum alloys

What is the corrosion product of aluminum?

White to gray powdery material

What two ways can corrosion of aluminum be removed?

1. Mechanical polishing

2. Abrasive brushing

What are the three main methods of protection of aluminum?

1. Chemical coating

2. Paints

3. CPC (corrosion preventive compounds)

What is an electrochemically applied oxide coating used for protecting of metals?


What are the lightest structural metals used for aircraft and missile airframes?

Magnesium alloys

What are the corrosion products of magnesium alloys?

White powdery snow-like mounds

How can the corrosion of magnesium alloys be diminished?

Use of proper protective finish

What six types of corrosion is aluminum alloy susceptible to?

1. Pitting

2. Intergranular

3. Exfoliation

4. Stress

5. Fatigue

6. Fretting

What is the corrosion appearance of aluminum alloy?

White to gray powder

What type of corrosion is magnesium alloy susceptible to?


What are three corrosion appearances of magnesium alloy?

1. White powdery

2. Snow-like mounds

3. White spots

What two types of corrosion is carbon and low alloy steel susceptible to?

1. Pitting

2. Intergranular

What is the corrosion appearance of carbon and low alloy steel?

Reddish-brown oxide (rust)

What five types of corrosion is stainless steels susceptible to?

1. Crevice corrosion

2. Pitting

3. Stress

4. Intergranular

5. Uniform surface

What is the corrosion appearance of stainless steels?

Rough surface

What type of corrosion is titanium alloy susceptible to?

Highly corrosive resitant

What is the corrosion appearance of titanium alloy?

Colored surface oxides develop above 700 F.

What type of corrosion is cadmium susceptible to?

Uniform Surface Corrosion

What are the two corrosion appearances of cadmium?

1. White powdery deposit

2. Black/brown molting of surface

What type of corrosion is chromium susceptible to?


What type of corrosion is nickel-base alloy susceptible to?


What is the corrosion appearance of nickel-base alloy?

Green powdery deposit

What two types of corrosion is electroless nickel susceptible to?

1. Pitting

2. Uniform surface

What two types of corrosion is copper-base alloy, brass, and bronze susceptible to?

1. Surface

2. Intergranular

What are the two corrosion appearances of copper-base alloy, brass, and bronze?

1. Blue powdery deposit

2. Green powdery deposit

What type of corrosion is silver susceptible to?

Will tarnish in the presence of sulfur

What is the corrosion appearance in silver?

Brown to black film

T/F. Gold is highly corrosion resistant.


What is the corrosion appearance in gold?

Deposits cause darkening of reflective surfaces

What is the corrosion appearance in tin?

Whisker-like deposits

What is used as a coating to protect steel hardware, such as bolts, washers, and screws?


What is used as a protective plating?