Ceramics are known for their high hardness, making them ideal for applications like cutting tools and wear-resistant surfaces. They are also brittle and have low ductility, but their hardness and resistance to heat are notable features.
Which material is a common example of a ferrous alloy?
A Steel
B Copper
C Aluminum
D Brass
Steel is a ferrous alloy, meaning it contains iron as its base metal. It is widely used for its strength, hardness, and versatility in applications ranging from construction to manufacturing tools and machinery.
Which type of steel is known for its corrosion resistance?
A Cast iron
B Stainless steel
C Tool steel
D Carbon steel
Stainless steel contains chromium, which forms a protective oxide layer on the surface, making it highly resistant to corrosion. This property makes stainless steel ideal for use in harsh environments, such as kitchens and medical equipment.
What is the key advantage of using cast iron over steel?
A Malleability
B High ductility
C Good castability
D High strength
Cast iron is favored for its excellent castability, meaning it can be easily molded into complex shapes. This makes it ideal for applications like engine blocks, pipes, and other heavy machinery components, where complex shapes are required.
Which of the following is a characteristic of high-carbon steel?
A Low hardness
B High ductility
C Low strength
D High hardness
High-carbon steel is known for its hardness and wear resistance, making it suitable for tools, knives, and other applications requiring high durability. However, it is less ductile than low-carbon steel, which can limit its workability.
Which of these is a common use for ceramics in engineering?
A Cutting tools
B Electrical wiring
C Structural beams
D Bearings
Ceramics are commonly used in cutting tools because of their high hardness and resistance to wear. They can maintain sharp edges and perform well at high temperatures, making them ideal for machining hard materials.
What is the primary factor that determines the brittleness of cast iron?
A Alloying elements
B Heat treatment
C Carbon content
D Grain size
The brittleness of cast iron is primarily due to its high carbon content, which forms graphite flakes in the microstructure. While these flakes improve castability, they reduce the material’s toughness and make it more brittle.
Which of the following is a property of tool steel?
A High electrical conductivity
B High strength and hardness
C High ductility
D High corrosion resistance
Tool steel is known for its high strength and hardness, making it ideal for tools that need to withstand high wear, such as drills, dies, and cutting blades. It is designed to maintain sharpness and durability under tough conditions.
What is the key feature of high-speed steel (HSS) used in cutting tools?
A High melting point
B Good corrosion resistance
C Good electrical conductivity
D High hardness at elevated temperatures
High-speed steel (HSS) retains its hardness even at high temperatures, making it ideal for cutting tools that operate at elevated speeds. This property allows HSS tools to perform well in high-performance machining operations.
What distinguishes ceramics from metals in terms of electrical conductivity?
A Metals are better insulators
B Ceramics are insulators
C Ceramics are better conductors
D Metals have no conductivity
Ceramics are generally electrical insulators, unlike metals, which are good conductors of electricity. This property makes ceramics suitable for use in insulating materials and electrical components that require resistance to electrical flow.
What does the term “ductile fracture” describe in materials?
A Slow, gradual deformation before breaking
B Resistance to crack growth
C Rapid temperature change
D Sudden, brittle breaking
Ductile fracture is characterized by significant plastic deformation before failure. Materials exhibiting ductile fracture undergo stretching or necking, absorbing more energy before eventually breaking, which contrasts with brittle fracture that occurs suddenly without much deformation.
What is the primary purpose of heat treatment in steel?
A Increase electrical conductivity
B Increase corrosion resistance
C Reduce carbon content
D Modify microstructure for desired properties
Heat treatment in steel is used to modify its microstructure to achieve desired properties such as hardness, strength, or toughness. Processes like annealing, quenching, and tempering are commonly used to tailor steel’s performance for specific applications.
Which steel is used for making structural components exposed to high temperatures?
A High-temperature steel
B Carbon steel
C Stainless steel
D Tool steel
High-temperature steel is designed to withstand extreme heat and maintain strength and integrity under high-temperature conditions. These steels are used in applications such as power plants and engines, where materials are exposed to elevated temperatures.
What is the main benefit of adding alloying elements to cast iron?
A Increase ductility
B Improve castability
C Improve strength and wear resistance
D Increase corrosion resistance
Alloying elements such as chromium, nickel, and molybdenum are added to cast iron to improve its strength, wear resistance, and toughness. This allows cast iron to be used in more demanding applications like engine blocks and machinery.
Which type of steel is used for making cutting tools and drills?
A Alloy steel
B High-speed steel
C Stainless steel
D Mild steel
High-speed steel (HSS) is used for making cutting tools and drills because of its ability to maintain hardness even at high temperatures, allowing it to perform well in high-speed machining processes without losing sharpness.