ABSTRACT
The quality of chemically bonded sand cores used during the manufacturing process of cast components is highly
dependent on the properties of the sand, which constitutes the refractory base media of the core. One of the main
advantages of the application of different types of sands as molding aggregates that after casting, they can be reclaimed and can be used again during core shooting. The properties of the sand, however, could be remarkably
changed during the casting and reclamation processes. This study aims to investigate the effects of the properties
of the base sand on the mechanical strength and thermal distortion properties of samples made from new and
thermally reclaimed silica sand. For this purpose, particle size analysis, specific surface area, and loss on ignition measurements, as well as differential thermal analysis coupled with thermogravimetry, were executed on the
base sands, and the sand grains were analyzed with scanning electron microscopy and X-ray diffraction. Test
pieces were made with hot box and cold box technology for bending and hot distortion tests. It was found that by
the utilization of reclaimed sand, cores with higher average bending strength and lower thermal deformation can
be produced. These differences can be traced back to the more advantageous granulometric properties, lower impurity
content, and lower thermal expansion of thermally reclaimed sand.
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INTRODUCTION
Sand cores are extensively used in the foundry industry to form inner cavities and holes during the manufacturing of cast components. These disposable mold parts can be considered as composites typically made from natural or, in some cases, artificial sands as aggregate filler materials whose grains are bound together by organic or inorganic binders. With the aid of sand cores, cavities with high complexity could be formed, which is substantial during the manufacturing of automotive components like cylinder heads and engine blocks.
http://www.pfa.org.pk/wp-content/uploads/2017/04/The_effect_of_sand_quality_on_the_bendin-1.pdf
