Lost foam casting
01.08.2012
First workshop’s line-up of casting on LFC-technology – Lost-Foam casting was brought into operation.
The complex’s body:
Model area; casting area; spectrographic and metallographic laboratories; final processing area.
Design output: 900 tons of valid casting per year.
The weight of serial steel casting is from 0,050 up to 100 kg.
Low-carbon and alloyed steels, grey and high-tensile cast iron, aluminium alloys and also alloys on copper base are applied as casting materials.
Production Stages:
Block-scheme
of production process.
A mold
First stage is production of an aluminium mold in a compliance with the cast’s or details drawing.
A model
Slightly foamed polystyrene is blown into a cavity of a mold, which then is being placed to an autoclave and is processed with steam and after that is cooled off with water. When a form is cooled to room temperature, a finished model is retrieved. This is an exact copy of a future detail. Then the models are attached with glue to a foam-polystyrene bar – an ingate, and by that casting cluster composed of 5-6 casts is agglomerated. The next stage is painting a cluster with gas permeable non-stick paint with further drying in drying chamber.
Casting clusters after having already dried out are placed to special moulding boxes and are carefully powdered with quartz sand. After this process degassing of a moulding box takes place at a vibrating (flow) table. This is a very responsible stage in a whole process as percentage of casting rejects (defective goods depends on exactly this stage).
A molten metal is casted into quartz pots that are placed over a casting cluster which is formed into a moulding box. The metal precisely duplicates a model’s shape while burning polystyrene out in the sand. After casting the finished clusters cool down and are retrieved from moulding boxes afterwards.
The castings are separated from a bar and with the help of shot-blasting machine and technology casting rejects are exposed. Further thermic normalization is done and shot-blasting technology for metals is repeatedly applied.
Final quality control ends up all the stages.