Essentials of Manufacturing

Information, coverage of important developments and expert commentary in manufacturing.

Power Transmission

Gear drives, bearings, motors, clutches, couplings, machine controls, sensors and components.

Machine Design

How-to, in-depth technical articles for machine design engineers

Chemical Engineering

The industry gateway for chemical engineering and plant operations.

more free magazines

Similar to plaster mold casting, the pattern used in ceramic mold casting is made of plaster, plastic, wood, metal or rubber. A slurry of ceramic is poured over the pattern. It hardens rapidly to the consistency of rubber. This can be peeled of the pattern, reassembled as a mold. The volatiles are removed using a flame torch or in a low temperature oven. It is then baked in a furnace at about 1000 °C (1832 °F) yielding a ceramic mold, capable of high temperature pours. Additionally, the pour can take place while the mold is until hot.

Tolerances can be held to 0.4 %, surface finishes can be better than 2 - 4 µm (.075 - .15 µin). Add 0.3 mm (.012 in) for parting line tolerances. Wall thickness can be as small as 1.25 mm (.050 in), and the weights can range from 60 g (2oz) to a ton. Draft allowance of 1° is recommended.

This process is expensive, but can eliminate secondary machining operations. Typical parts made from this process include impellers made from stainless steel, bronze, complex cutting tools, plastic mold tooling.