Question
Download Solution PDF________ is used to minimise splash and turbulence when metal is flown into a down sprue.
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFExplanation:
Gating System:
- It refers to the channels through which the molten metal flows to the die cavity.
- Its key objective is to ensure its smooth and complete flow from the ladle to the mould cavity.
- To achieve perfect castings, it is important to have a gating system that is well designed.
Important elements related to the Gating system are:
Cope: Top half of the mould.
Drag: Bottom part of the mould
Mould Cavity: Gap created in mould using pattern
Pouring Cup: From here metal is poured. It is used to minimise splash and turbulence when metal is flown into a down sprue.
Sprue: Pipe shaped. From the pouring basin, the metal flows into the sprue.
Runner: The horizontal hollow channels that connect the bottom of the sprue to the mould cavity.
Ingate: The region where runner joins with the cavity
Riser: Excess metal poured into the mould flows into these cavities. They act as reservoirs, as the metal solidifies inside the cavity, it shrinks, and the extra metal from the riser flows back down to avoid holes.
Hence, A and B in question are Riser and Runner respectively.
Additional Information
Gating ratio = a : b : c
Where, a = cross-sectional area of sprue; b = total cross-sectional area of runner; c = cross-sectional area of ingates.
|
Pressurized gating system |
Unpressurized gating system |
|
The gating ratio may be of the order of 3:2:1 |
The gating ratio may be of the order of 1:3:2 |
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Air aspiration effect is minimum. |
Air aspiration effect is minimum |
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The volume flow of liquid from every ingate is almost equal. |
The volume flow of liquid from every ingate is different |
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Smaller in volume for a given flow rate of the metal. |
Larger in volume for a given flow rate of the metal. |
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As velocity is high, severe turbulence may occur at corners. |
As velocity is low, turbulence is reduced. |
Last updated on May 12, 2025
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