What is Mercast Process - Applications, Advantages and Disadvantages of Mercast
Mercasting / mercast process is an improvement in precision investment casting. In this manufacturing process, the pattern is made of mercury is used to make mould. The mercury pattern is formed in a special aluminium mould. At normal room temperature, the mercury is filled into the master mould. Then the whole unit is cooled to a temperature below -38°C, eventually the mercury gets solidify. The frozen mercury pattern is then removed from the master mould and dipped into series of special slurries to form a harder ceramic shell around them.
The temperature the mercury then allow to rise, the liquefied mercury then retrieved from mould. The obtained mould is then used for investment casting.
- Types of pattern materials
- Types of Pattern Allowance and Its Reason
Advantages and applications of mercast
- Excellent quality. It gives better surface finish.
- Mercury did not expand when it changed from solid form to liquid form. So there is no any unwanted stress inside the mould during pattern removal by melting.
- Mercury can flow into very thin sections of the master mould, hence form a very detailed pattern.
- It gives close tolerance. Usually the mercasted shape does not need further finishing process.
- The mercury can be reused to making the Pattern again.
Disadvantages of mercast
- Mercast process is expensive
- Pattern must be kept at low temperature; it is not desirable in common foundry operation.
- Mercury is hazardous to health.
- Time-consuming process.