INFLUENCE OF TEMPERATURE ON THE INTERACTION KINETICS BETWEEN MOLTEN ALUMINIUM ALLOY AL99.7 AND TOOL STEEL H11

Abstract

Hot-work tool steels are used in casting and hot-forming processes and are subjected to thermal, mechanical and chemical stresses that can cause damage to various parts of the tool. Therefore, knowledge of the interaction between tool steel and molten aluminium alloy is necessary to extend the life of the tool. The present work was carried out to predict the influence of temperature on the interaction kinetics between tool steel and molten aluminium. To investigate the effect of temperature on the dissolution rate of tool steel in molten aluminium and the rate of formation of interaction layers, DSC analysis was performed at two different temperatures, 670 °C and 700 °C, for 12 h. The results were corroborated and supported by a detailed microstructure analysis.
 It was found that very small temperature changes, in this case 30 °C, significantly affect the kinetics of the interaction layer’s formation between the tool steel H11 and molten aluminium Al99.7. All test methods show a pronounced influence of the test temperature. A significantly faster dissolution was observed in the DSC curve, with the slope of the curve being larger for the specimen tested at 700 °C, which was also confirmed by measurements of the thicknesses of the interaction layers. The thickness of the composite layer was almost the same in both cases, and the temperature has no effect on this layer. The types of interaction layers do not differ from each other.