Materials Science & Technology Flashcards

Which property describes a material's ability to return to its original shape after deformation without permanent change?

Answer: Elasticity

Elasticity is the material property that allows a substance to fully recover its original dimensions upon removal of the applied load.

Carbon fiber composite materials used in O&P are reinforced with carbon fibers primarily to improve which mechanical property?

Answer: Stiffness-to-weight ratio

Carbon fiber composites have an exceptionally high stiffness-to-weight ratio, making them ideal for energy-storing prosthetic feet and lightweight orthotic shells.

Thermoplastic materials used for custom orthotics are typically formed at temperatures between:

Answer: 150–180°F (65–82°C)

Low-temperature thermoplastics commonly used for splints and orthotics soften and become moldable at 150–180°F, allowing direct patient molding.

What is the primary advantage of using titanium over steel in prosthetic structural components?

Answer: Higher strength-to-weight ratio

Titanium offers a superior strength-to-weight ratio compared to steel, allowing structurally sound prosthetic components at significantly reduced mass.

Viscoelastic materials exhibit which combination of properties?

Answer: Both viscous (time-dependent) and elastic (recoverable) behavior

Viscoelastic materials exhibit rate-dependent behavior, combining elastic recovery with viscous energy dissipation, as seen in gel liners and dynamic foot keel materials.

Which type of polypropylene is most commonly used for thermoplastic AFO fabrication?

Answer: Copolymer polypropylene

Copolymer polypropylene is preferred for AFOs because it offers better impact resistance and flexibility at thin sections compared to homopolymer.