General Properties and Applications of Metals and Alloys

Flashcards summarizing key concepts, properties, and applications of metals, alloys, polymers, and ceramics from the lecture notes.

What is the effect of increasing carbon content in iron alloys?

Higher carbon content improves strength, hardness, and wear resistance but reduces ductility, weldability, and toughness.

What do the first two digits in the AISI four-digit code for carbon steels represent?

The first two digits indicate the alloying elements present in the steel.

What is the composition of low-carbon steel?

Low-carbon steel contains less than 0.30% carbon.

What are the typical properties of high-strength low-alloy (HSLA) steels?

They have low carbon content (<0.30%), improved strength-to-weight ratio, and a dual-phase microstructure.

What is the primary use of stainless steels?

Stainless steels are used for their resistance to corrosion.

What characterizes tool and die steels?

Tool and die steels generally have a carbon content between 0.5% and 1.5% and are known for their high impact toughness and wear resistance.

What are the advantages of aluminum alloys over steel in automotive applications?

Aluminum alloys provide significant weight savings, improved fuel economy, and reduced pollution.

What is one drawback of nonferrous metals like aluminum compared to steel?

Nonferrous metals are more expensive than steel, costing 2-3 times as much.

What properties do shape-memory alloys display?

Shape-memory alloys can return to their original shape upon heating after being plastically deformed.

What are the typical applications of polymers and plastics?

Polymers are used in food and beverage containers, medical devices, houseware, textiles, and automotive components.

How do additives affect the properties of plastics?

Additives like plasticizers improve flexibility but may decrease strength; fillers can reduce cost while enhancing strength.

What is the difference between thermoplastic and thermosetting polymers?

Thermoplastics are moldable and can be reshaped, while thermosetting polymers have a permanent shape after curing.

What defines composite materials?

Composite materials consist of fibers, a matrix, and an interface, where the fibers provide strength, and the matrix protects and supports them.

Why is interfacial strength important in fiber-reinforced composites?

The strength of the bond between the fiber and matrix determines the efficiency of load transfer.

What is a common property of ceramics?

Ceramics are brittle and sensitive to cracks and porosity but have high strength and temperature resistance.

What applications utilize ceramic matrix composites?

Ceramic matrix composites are used in high-temperature and high-strength applications, such as aerospace components.