Ceramic Casting - Shaw Process
If accuracy is highly important and if the series are limited, the Shaw process is an excellent choice. for example shrouded impellers for centrifugal pumps.
The process uses a very pure strong silica gel to bond ceramic refractory powders to form a mold suitable for molten steel. The exceptional permeability of the fired mould not only minimises thermal shock but also allows free passage of air, eliminating the need for venting. High temperature thermal stability also minimises mould distortion after pouring, resulting in extremely accurate castings . Because a "split-mould" technique is used. pattern equipment is less expensive than for the expendable pattern process.
The unique feature of the Shaw Process is the "microcrazing" that is created when the casting solution is burned off to dry the mould. This enables the Shaw Process mould to retain its original volume and dimensional accuracy.
The major advantages of the Shaw Process castings include:
- Dimensional accuracy to 0,25 mm tolerance.
- Reduced machining costs by eliminating preliminary machining.
- Increased output by reducing machining time.
- Extremely fine surface detail.
- Increased design possibilities, even for high alloy steels.
- High integrity castings.
- Relatively low pattern costs.
- Aircraft and aerospace components to class 1A
- Pump industry with the application of shrouded impellers for in cast iron, cast steel, stainless and alloys like Monel(R) and Hastelloy(R) .
- Parts for machinery building industries with batches from 10 to some 100
- Precision dies for plastic components, buttons, bottle tops, door handles, light bulbs, heat plates for the sugar processing industry, rubber moulding industry equipment and the production of aluminium.
- Propellers and marine parts
Depending on the geometry, Shaw Process castings can be made up to a maximum weight of approx. 50 - 60 kg in material specification scheme "available materials for Shaw process."