What is the next step after the mould is heated in the investment casting process?

• A. Liquid metal is poured into the mould until it cools
• B. The mould is crushed
• C. The pattern is reintroduced
• D. The slurry is reapplied

Answer: (A)

In investment casting, after the wax pattern has been burned out by heating, the ceramic mould is ready to receive metal. The next step is to pour molten metal into the mould until it fills the cavity and then let it cool and solidify. Heating serves to remove the pattern and preheat the shell, reducing thermal shock and improving metal flow into the cavity. Once solidified, the mould is broken to reveal the casting and gates are removed in later finishing steps. The other options don’t fit this stage: crushing the mould happens when you retrieve the casting, not during pouring; reintroducing the pattern isn’t part of the process after burnout; and reapplying slurry is part of forming the mould, not a post-burnout action.