Breathable Salt Core for Casting Hollow Parts
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Solution Overview
Problem
Conventional salt cores used in casting processes for hollow components, such as internal combustion engine pistons, face issues with incomplete filling due to residual gases interfering with molten metal flow, requiring complex processes and increased costs to address gas escape.
Innovation Solution
A breathable salt core is formed with a gap between powder-molded salt particles, allowing residual gases to be retained without the need for grooves, using a lower molding pressure and omitting calcination and machining steps, ensuring a charging density of 88% to 92% for effective gas retention and strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high pressure press is used to increase charging density for ensuring strength during machining, then the strength of salt core is improved, but the gap between salt particles is reduced making gas retention difficult
Solution Approach 1:
The patent changes the charging density parameter from conventional high density (96-98%) to a lower range (88-92%), which creates sufficient gap between salt particles for gas retention while maintaining adequate strength through optimized powder molding parameters and salt particle characteristics
2Strength
If calcination is performed to increase strength, then the strength of salt core is improved, but the production process becomes complicated and cost increases
Solution Approach 1:
The patent extracts the calcination step from the production process by using salt particles with controlled characteristics and optimized powder molding parameters that enable the salt core to achieve sufficient strength without thermal treatment, thereby simplifying the production process and reducing costs
3Reliability
If groove is provided in salt core for gas escape, then incomplete filling is prevented, but the production process becomes complicated and cost increases
Solution Approach 1:
The patent enables the salt core to automatically retain and manage residual gas through the natural gaps between salt particles, eliminating the need for人工-designed grooves or channels. The salt core structure itself provides the gas retention function through its inherent porous characteristics
Solution Approach 2:
The patent utilizes the porous structure formed by gaps between salt particles to provide gas retention capability, allowing residual gas to enter and be held within the salt core matrix without requiring additional structural features like grooves
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach prevents incomplete filling, simplifies the production process, and reduces costs by allowing gas retention within the salt core, ensuring good flowability and strength without the need for additional processing steps or additives.
Implementation Method 1
a gap that can retain residual gas within the cavity pushed out by molten metal in a casting process is formed between the innumerable salt particles
Implementation Method 2
the breathable salt core, which is formed by powder molding innumerable salt particles into a predetermined shape
Data Source
AI summary
A breathable salt core is provided that is placed in a cavity of a casting mold in order to mold a hollow part of a cast product and that is dissolved and removed after casting, the breathable salt core being formed by powder molding innumerable salt particles into a predetermined shape corresponding to the hollow part, wherein a gap that can retain a gas remaining in the cavity in a casting process is formed between the innumerable salt particles that have been powder molded. The breathable salt core thus manufactured assures that residual gas within the cavity pushed by the molten metal to enter the gap formed between salt particles of the salt core, thereby avoiding any incomplete filling of the molten metal, and which can be formed with a simple production process at a low cost.