Question

Arrange the following as per the steps followed in Aluminium Casting by the Indirect lost-wax. A. The entire mass is encased in a plaster of Paris investment. B. All the plaster investment material has been broken away from casting. C. Covering the plaster form with a thin wax coating. D. Gates, channels, and risers are then attached to the model. E. The mold is then baked to melt away the wax and molten metal is poured to occupy the space vacated by the ‘lost' wax. Choose the correct answer from the options given below:

• A. A, B, E, C, D
• B. B, E, A, D, C
• C. C, D, A, E, B
• D. D, C, B, E, A

Hint:

Remember the sequence of Indirect Lost-Wax Casting: \[ \boxed{ \begin{aligned} \text{Wax Coating} &\rightarrow \text{Prepare Wax Model}, \text{Gates and Risers} &\rightarrow \text{Provide Metal Flow}, \text{Investment} &\rightarrow \text{Plaster of Paris}, \text{Burnout} &\rightarrow \text{Wax Melts, Metal Poured}, \text{Break Investment} &\rightarrow \text{Finished Casting}. \end{aligned} } \] Mnemonic: “Wax $\rightarrow$ Gates $\rightarrow$ Investment $\rightarrow$ Burnout $\rightarrow$ Break.”

Answer 1

The Correct Option is C

Concept: The Indirect Lost-Wax Casting process involves first preparing a plaster model, coating it with wax, attaching a gating system, investing it in plaster, melting out the wax, pouring molten metal, and finally breaking the investment to obtain the casting. The sequence ensures that the molten metal exactly replaces the wax model, producing an accurate metal replica.

Step 1: Prepare the wax model. A thin layer of wax is first applied over the plaster form. \[ \boxed{\text{Covering the plaster form with a thin wax coating}} \]

Step 2: Attach the gating system. Gates, runners, channels, and risers are attached to provide passages for molten metal. \[ \boxed{\text{Attach gates, channels and risers}} \]

Step 3: Invest the model. The complete wax assembly is enclosed in a plaster of Paris investment. \[ \boxed{\text{Encase in plaster investment}} \]

Step 4: Burn out the wax and cast the metal. The mould is heated so that the wax melts away, and molten aluminium is poured into the cavity. \[ \boxed{\text{Bake the mould and pour molten metal}} \]

Step 5: Finish the casting. After cooling, the plaster investment is broken away to reveal the finished casting. \[ \boxed{\text{Break away the investment}} \] Thus, the correct sequence is \[ \boxed{C,\ D,\ A,\ E,\ B} \] Hence, \[ \boxed{\text{(C)}} \]