To establish a manufacturing process for aluminum foams at low costs, in this study, we applied twin-roll casting to manufacture aluminum foams with the precursor method and performed evaluation of its porosity and cell morphology. Pure aluminum and alumina powders (thickening agents) and titanium hydride powder (foaming agent) were added to ADC12 aluminum alloy melt, and the melt was mixed. The melt was then fed into a vertical type large twin-roll caster to obtain a foamable precursor. The specimen cut from the precursor was placed and heated in an electric furnace at 675℃ to obtain aluminum foams. Density measurement, observation of the cross-section area and cell morphology analysis of the aluminum foams were carried out. Aluminum foams with average porosity of 60%, could be obtained by precursor method using twin-roll casting. The average diameter and number of pores were 1.34 mm and 52 pores, respectively.

  In the die design of high pressure die casting (HPDC), in order to prevent the casting from the warpage, it is essential to predict the ejection force of each ejector pin before locating it. Recently, Shiga et al. revealed that their developed elasto-plastic-creep model is more accurate than conventional elasto-plastic models to estimate the thermal stress of casting during cooling with constraint of dies.

  In this study, by using the elasto-plastic-creep model, thermal stress analysis was conducted to predict the force of each ejector pin in the HPDC process. As a result, the force could be estimated within the error of 30% in respect to the measured value. It could also be predicted that increasing in the curing time increases the force.