Abstract
Quarzsand is the most commonly moulding material used in casting technologies. Low commodity prices, good technical properties and easy availability make it very attractive to most foundries. Constantly increasing customer demands on the casting surface of increasingly complex castings provoke to think of alternative moulding materials. Furthermore, the availability of natural high-purity quartz-sand is limited. The purity has great influence on the physical properties and hence on the quality of the sand. In the foreseeable future rising prices are to be expected. The aim of this thesis is to identify potential alternative moulding materials, the investigation of their properties and their influence on the casting. Furthermore of interest are the mechanical properties of different core-sand mixtures and their impact on the solidification behaviour. Bauxite-, chromite-, zircon-sand, as well as metal granules and mixtures of metal granules with silica- and zircon sand were tested to examine their mechanical properties. Tests of the bending strength were therefore performed to determine the mechanical propeties of the samples. The investigation of metal granules was of special interest. The influence on the solidification behaviour was determined by casting trials which were conducted with an aluminium alloy as well as ductile cast iron. In summary, bauxite- and zirkonium-sand stand out with their very high form stability, especially when using optimized grain size distribution. However, by core shooting, metal granules are problematical during filling of core moulds. Nevertheless, their bending strength is similar to that of quarz-sand-mixtures. Notable is their quenching effect during casting. This results in a very hard surface of the cast parts in the case of ductile cast iron and with a locally decreased dendritic arm spacing in Al-alloys.
Translated title of the contribution | Potential of new moulding materials for sand cores |
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Original language | German |
Qualification | Dipl.-Ing. |
Supervisors/Advisors |
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Award date | 21 Oct 2016 |
Publication status | Published - 2016 |
Bibliographical note
embargoed until nullKeywords
- sand cores
- bauxite
- zircon
- metal granulate