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Currently offered devices for the hardness measuring or indices of the mould strength, are presented in the hereby paper. The presented results allow to compare approximately the indications of individual devices of different types.The description of the author’s own microprocessor tester for the quality assessment of the sand foundry moulds, is shown. On the bases of the measurements results it is possible, to evaluate indirectly, the mould apparent density in the selected points, as well as several other properties.

Currently offered devices for the hardness measuring or indices of the mould strength, are presented in the hereby paper. The presented results allow to compare approximately the indications of individual devices of different types. The description of the author's own microprocessor tester for the quality assessment of the sand foundry moulds, is shown. On the bases of the measurements results it is possible, to evaluate indirectly, the mould apparent density in the selected points, as well as several other properties. [ABSTRACT FROM AUTHOR]

Under the subject of this study, it was found that the growth of graphite in eutectic solidification is the most important factor. Also, shrinkage cavity increases in hypereutectic composition because the crystallisation volume of graphite in eutectic solidification becomes smaller. In addition, the Al amount contained in spheroidal agent or molten metal works negatively for shrinkage cavity, which could be said the same for P, Mo and Cr. As for the shrinkage cavity in non-alloyed ductile iron, the metal supply resistance PMSR is the most significant element in regard to the occurrence of shrinkage cavity. For tight mould, there is no relationship between modulus and shrinkage cavity while the PMSR of a product is the dominant factor. This theory of PMSR can be applied to final solidification loops of products based on simulation. Based on this, it became possible to make shrinkage cavity free products without a riser. [ABSTRACT FROM AUTHOR]