AM Material Selection & Properties 3

Question 1

What is the function of an alclad coating on aluminum sheet?

Accepted Answer

Provide sacrificial corrosion protection to the core alloy

Answer

Alclad is a thin layer of pure aluminum bonded to a stronger aluminum alloy core; the pure aluminum corrodes preferentially, protecting the structural core.

Question 2

Which non-destructive testing method is best suited for detecting subsurface cracks in non-ferrous metals?

Accepted Answer

Eddy current inspection

Answer

Eddy current inspection can detect both surface and subsurface discontinuities in conductive non-ferrous materials without requiring magnetic properties.

Question 3

What does a material's modulus of elasticity (Young's modulus) describe?

Accepted Answer

Stiffness—ratio of stress to strain in the elastic range

Answer

Young's modulus is the ratio of applied stress to resulting elastic strain, quantifying a material's stiffness or resistance to elastic deformation.

Question 4

Which type of stainless steel is most commonly used for aircraft exhaust components due to its high-temperature oxidation resistance?

Accepted Answer

Austenitic stainless steel

Answer

Austenitic stainless steels (300 series) maintain strength and resist oxidation at elevated temperatures, making them suitable for exhaust systems.

Question 5

What is the purpose of shot peening an aircraft component?

Accepted Answer

Introduce compressive residual stresses to improve fatigue life

Answer

Shot peening bombards the surface with small steel or glass beads, inducing compressive residual stresses that retard fatigue crack initiation.

(AM) Aircraft Maintenance Certification Practice Test

(AM) Aircraft Maintenance Certification Practice Test

AM Material Selection & Properties 3