Chapter 9 - Fundementals of Casting

What is the primary purpose of casting in manufacturing?

To create a part through solidification of material.

What are the three engineering materials that solidification processes can be classified into?

Metals, ceramics (specifically glasses), and polymers (including polymer matrix composites).

What are the three main steps involved in the casting process?

Melt the metal, pour it into a mold, and let it freeze.

What is the main advantage of using casting in manufacturing?

Can create complex part geometries and both external and internal shapes.

What are some disadvantages of casting?

Limitations on mechanical properties, poor dimensional accuracy, and safety hazards due to hot molten metals.

Name some examples of large parts made by casting.

Engine blocks, machine frames, railway wheels, and church bells.

What is a foundry?

A factory equipped for making molds, melting and handling molten metal, performing the casting process, and cleaning the finished casting.

What are the two forms of molds used in casting?

Open molds and closed molds.

Describe the function of the 'gating system' in casting.

The channel through which molten metal flows into the mold cavity.

What role does a riser play in the casting process?

It is a reservoir in the mold that provides liquid metal to compensate for shrinkage during solidification.

What does Chvorinov's Rule relate to in the casting process?

It relates to solidification time, indicating that larger volume to surface area ratios solidify more slowly.

What is the pattern shrinkage allowance in casting?

The amount by which the mold is made larger to account for solidification shrinkage and thermal contraction.

What is directional solidification in casting?

The process of ensuring that the regions of the casting distant from the metal supply freeze first.

What are chills in the context of casting?

Internal or external heat sinks that promote rapid freezing in specific areas of the casting.

What is the significance of controlling the cooling rate in the solidification of metals?

It affects the grain structure and mechanical properties of the casting.