MICROPOROSITY AND LOST-WAX INVESTMENT-CAS TING

Using simple models consisting of spheres and cylindrical rods the inf luence of various factors (e.g. melt and mould temperature, dimensions of model) on shrinkage porosity was investigated. Because of consider able scattering of measured values only statistical evaluation brought reliable results. Variation of influencing factors acts generally in opposite direction whether heavy or small cross-sectioned parts of a c ast item are considered. Mould (flask) temperature has a more pronounc ed influence on porosity than casting (melt) temperature. For evaluati ng the influence of the shape of models on porosity characteristic for m factors were used.