09 Materials Processing Free Online FlashCards

What can materials processing change besides a component’s shape?

Processing changes a material’s shape and can also change its structure, which influences its properties.

Why is casting useful for making complex shapes?

Casting can produce complex shapes, including parts that would be difficult to make by cutting or forming.

How does faster cooling generally affect cast-metal structure?

Faster cooling generally produces a finer solidification structure in cast metal.

How can pores in a casting affect its mechanical performance?

Pores and other casting defects reduce effective load-bearing area and can provide sites where cracks begin.

What is a common property trade-off caused by cold working?

Cold working usually increases strength and hardness but reduces ductility; it can also make properties directional.

Why can hot working allow large shape changes with less work hardening?

Recovery and recrystallization can occur during hot working, reducing work hardening and allowing large shape changes.

Why does machining control more than a part’s dimensions?

Machining removes material to create shapes, dimensions, or finishes, but cutting can also alter near-surface properties and residual stresses.

What can annealing do to cold-worked metal?

Annealing can soften cold-worked metal, improve ductility, and reduce residual stresses; recrystallization may form new, relatively strain-free grains.

What is a possible result and trade-off of quenching steel?

Quenching suitably prepared steel rapidly can form hard martensite, but may also leave it brittle and stressed.

Why is quenched steel tempered?

Tempering reheats quenched steel below its transformation range to reduce brittleness and improve the balance of hardness and toughness.

How does age hardening strengthen suitable alloys?

Age hardening forms fine particles through heat treatment; these particles impede deformation in suitable alloys.

How can flow during polymer processing affect directional properties?

Flow can orient polymer chains, strengthening a product in one direction while making its properties anisotropic.