The paper deals with the possibilities of using alkali silicate based inorganic binders for automotive industry aluminium castings production. In recent years, inorganic binders are coming back to the foreground and their manufacturers are developing new processes, which are starting to progressively supersede organic binder systems. Paper describes known knowledge about classic alkali silicate binders with focus on hardening processes and on improving their technological properties. Trends from the area of development and the use new alkali silicate based inorganic binders are also shortly described. As part of the experimental work, specific methods of producing samples were developed, with the help of which properties such as disintegration were subsequently evaluated by measuring abrasion and residual strengths. Characteristics such as residual compressive strength or shear strength at different thermal loads were also evaluated. When comparing the laboratory results with the results of de-coring in real conditions, a high degree of correlation was achieved, which makes it possible to determine the optimal recipe/procedure for the production of geometrically complex cores.
The naturally pressurized gating system was used for reoxidation suppression during aluminium alloy casting. A naturally pressurized gating system appears to be a suitable solution to reduce reoxidation processes, which was proven by our previous works. The disadvantage of this system is that without inserting deceleration elements, the melt velocity is supercritical. Therefore, the aim of paper is to find a proper way to reduce the melt velocity, which is the main parameter affecting the scale of reoxidation processes. For the purpose of the melt velocity reduction, labyrinth filters, foam filters and flat filters effect on the melt velocity and the number of oxides were investigated by numerical simulation software in the first stage of the experiment. After simulations observation, the effect of filters on the mechanical properties was investigated by experimental casts. The simulations and experimental casts proved that filters had a positive effect on the melt velocity reduction and it was associated with increased mechanical properties of castings. The best results were achieved by the foam filter.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.