What is the primary purpose of tempering steel after quenching?
A Reduce brittleness
B Increase ductility
C Increase hardness
D Increase strength
Tempering is performed after quenching to reduce brittleness by reheating the material to a lower temperature. This process allows the formation of more stable microstructures, improving toughness while maintaining strength.
Which of these materials is commonly welded using the MIG (Metal Inert Gas) process?
A Brass
B Stainless steel
C Cast iron
D Lead
Stainless steel is commonly welded using the MIG process due to its ability to produce clean, strong welds with good aesthetic appearance. MIG welding uses a continuous wire feed and an inert gas to shield the weld area.
What is the main advantage of powder metallurgy over traditional casting methods?
A More complex designs
B Requires high temperatures
C Less material wastage
D Higher production cost
Powder metallurgy involves compacting metal powders into molds and then heating them to form a solid part. This process produces less material wastage compared to casting, as it can create near‐net shapes with minimal trimming required.
What is the primary characteristic of a material with high weldability?
A High ductility
B Ability to form strong welds
C High strength
D Low melting point
High weldability refers to a material’s ability to form strong and durable welds without defects, such as cracks or porosity. Materials with good weldability include low‐carbon steels and certain alloys like aluminum.
What is a common application of powder metallurgy in industry?
A Gears and bearings
B Electrical circuits
C Structural components
D Packaging
Powder metallurgy is widely used to produce gears, bearings, and other parts that require complex shapes and high dimensional accuracy. It is particularly effective for parts that need to be cost‐efficient and durable.
Which type of welding is commonly used for joining thin metal sheets?
A MIG welding
B Shielded metal arc welding
C Spot welding
D Gas tungsten arc welding
Spot welding is commonly used for joining thin metal sheets by applying heat and pressure at localized points, making it ideal for applications such as automotive manufacturing where thin, sheet metals need to be welded.
What is the purpose of using flux in welding processes?
A To prevent oxidation
B To increase material strength
C To improve surface finish
D To cool the weld
Flux is used in welding to prevent oxidation and contamination of the weld area by forming a protective layer over the molten metal. This ensures clean and strong welds, particularly when using processes like arc welding.
Which of the following welding processes uses a non‐consumable electrode?
A Stick welding
B Flux‐cored welding
C TIG welding
D MIG welding
In TIG (Tungsten Inert Gas) welding, a non‐consumable tungsten electrode is used to create the arc. The filler metal is added separately, which allows for greater precision and control, making it ideal for thin materials.
What is the key benefit of using high‐carbon steel for toolmaking?
A Low cost
B High hardness
C High ductility
D High corrosion resistance
High‐carbon steel is used for toolmaking because it can be hardened to achieve high hardness, making it ideal for cutting tools, drills, and other implements that need to maintain sharpness and resist wear.
What property is most critical for materials used in high‐temperature applications?
A Ductility
B Electrical conductivity
C Corrosion resistance
D Thermal stability
Materials used in high‐temperature applications must have high thermal stability to maintain their strength and structure at elevated temperatures. This property is crucial for components in engines, turbines, and reactors.
What is the main benefit of using flux‐cored arc welding (FCAW)?
A High speed
B Clean welds
C Low cost
D High precision
Flux‐cored arc welding (FCAW) is a welding process that offers high deposition rates and is fast, making it ideal for applications requiring high productivity. The flux core helps protect the weld from contamination during the process.
In which application is powder metallurgy particularly advantageous?
A High thermal conductivity applications
B Low‐strength materials
C Large structural components
D Complex shapes with precise tolerances
Powder metallurgy is ideal for producing complex shapes with high precision and tight tolerances. It eliminates the need for extensive machining and can achieve intricate designs that are difficult to manufacture using other methods.
Which welding method is commonly used to join non‐ferrous metals like aluminum?
A MIG welding
B Stick welding
C Gas welding
D TIG welding
TIG welding is commonly used for welding non‐ferrous metals like aluminum, as it provides greater control over the heat input, producing high‐quality, clean welds without spatter.
What does the term “weldability” refer to in materials?
A Ability to deform plastically
B Ability to conduct electricity
C Ability to form strong, durable welds
D Ability to resist corrosion
Weldability refers to how easily a material can be welded, considering factors like its chemical composition, melting point, and thermal conductivity. Materials with good weldability form strong, defect‐free joints.
What is the main feature of powder metallurgy compared to casting?
A More complex shapes
B Ability to create near‐net shapes
C Lower cost
D Requires no heat treatment
Powder metallurgy allows the production of near‐net shapes, which reduces the need for further machining or material waste. This process is ideal for producing parts with intricate designs and high dimensional accuracy.