Investment casting technology is one of the foundry technologies enabling to achieve both very narrow dimensional casting tolerances (so called “net shape technology”) and also very complex casting shapes. The whole concept of the three years research joint project of Fimes,a.s. (aluminium investment casting foundry) and the Brno University of Technology, is focused to development of this technology. The main goal of this research is the implementation of the achieved results into daily Fimes foundry practice and thus to increase the foundry chances to address customers from aircraft, aerospace, defence and similar hi-tech industries. The whole project is divided into 7 parts following the main phases of investment casting technology:

1/ “Mother” die

Developed and tested the new software for simulation of wax filling into “mother” dies. This unique software should help the designers of dies to design the correct gating systems for wax injection to achieve high quality wax patterns “right in the first time”.

2/ Wax pattern

Detail laboratory analysis of several types of waxes suitable for thin wall wax patterns have been done at Blayson (UK) laboratory. The basic physical, rheological and technological properties of different waxes have been tested and the best versions recommended for its use at Fimes foundry.

3/ Ceramic shell mould

Detail laboratory analysis of several types of so far at Fimes used ceramic shell compositions have been done at the CARRD laboratory of IMERYS (Austria).Based on these results the optimal ceramic shell composition has been suggested (i.e. compositions of slurries and also stuccos for both primary and back up coats).

4/ Preparation of aluminium melt

Detail analysis of all technological operations connected with preparation of the melt for pouring has been done (i.e. purification, modification, grain refining and degassing). 5/ Pouring technique

In this part of the research the basic measurements of temperature fields of the system “ceramic mould – aluminium alloy” (pouring under air and also vacuum) have been done. Also optimal system of pouring technique for larger castings (up to 40 kg) is being developed. 6/ Filling the ceramic mould cavity by molten metal.

During these experiments especially designed test for measuring of metal fluidity (i.e. ability of the molten metal to fulfil the mould cavity) has been used.

Following to the first achieved results special “cage gating systems” for larger castings (up to 700 mm length) have been tested. All designs of these special gating systems have been proposed based on the results achieved by simulation of both filling mould cavities by molten Al alloy and also its solidification. 7/ Finishing operations

This part of the research is covering the monitoring of the whole process at the foundry which in the end should achieve the NADCAP certification (aircraft and aerospace level).