Casting Practice Test: Pouring - Gating Design, Melting Furnaces, Melting and Casting Quality — Flashcards

Pouring - Gating Design, Melting Furnaces, Melting and Casting Quality topics include: Aspiration and friction effects, velocity distribution, melting furnaces, metals gases, casting cleaning and sand castings product design.

A gating system is a series of passages that allow molten metal to flow into a mold cavity. A good gating system should ensure that the molten metal is distributed properly without excessive temperature loss, turbulence, gas entrapment, and slags. 

The main components of a gating system are: Pouring basin, Sprue, Well, Runner, Ingate. 

A poorly designed gating system can result in casting defects, such as:
Oxidation of metal
Cold shuts
Mold erosion
Shrinkages
Porosity
Misruns
Penetration of liquid metal into mold walls 

Here are some tips for pouring and gating design:
A high pouring temperature increases the amount of gas absorbed by the molten metal.
When gases are not allowed to escape, they can be trapped inside the casting and weaken it.
A pouring basin is the funnel-shaped inlet where metal is poured from the ladles into the mold.
The pouring basin helps to regulate the flow rate of liquid metal and reduces turbulence at the sprue entrance.
It also helps to separate sediment and slag before entering the sprue.