Development of an Experimental Setup to Investigate Influences on Component Distortion in Gravity Die Casting and a First Variation of Temperature Control Strategy

Abstract

Distortion (1), residual stresses and hot cracks can facilitate significant decreases in quality characteristics of casting products. Their reduction by a suitable component design (2) and process control is therefore desirable. In the casting process, these characteristics are assumed as a result of the combination of solidification shrinkage paired with the local self-feeding and the geometric constraints imposed on the component by the mold. In gravity die casting (3) of aluminum (4) with thermally well conducting and rigid metal molds, the control of solidification through a localized adjustment of the heat balance (5) appears to be a suitable approach to minimize these effects. The development of an experimental setup for the assessment of the interdependencies of the alloy, casting geometry and cooling are described in this work. A first series of experiments with A356 aluminum alloy and the introduction to the different methods of evaluation are presented. Furthermore, an approach to improve the understanding of the underlying mechanisms is outlined.

Description of component distortion in aluminum gravity die casting as a result of hindered shrinkage and evaluation of numerical predictions

“…These were cast at different mold temperatures of 30 °C, 150 °C and 300 °C and demolded the next day at room temperature (here assumed to be 30 °C). No significant correlations between mold temperature and the magnitude of distortion were found [12]. Subsequently, four more series of eight castings each were poured.…”

“…For the evaluation, series of eight castings of the same condition were used in each case. For the experiments, the modular experimental mold from the earlier work on the influence of heat balance was reused together with the oil flow temperature control [11,12]. The modules used in this work allow demolding up to temperatures close to the solidus temperature by using a tear-off inlet, and ejectors, Figure 1 on the right.…”

“…In a first step, gravity die casting of aluminum is investigated as a basis for the consideration of permanent mold casting processes. In the experimental set-up used here, the influences of the heat-balance on component distortion have already been considered and published [11,12]. In these investigations, in which the casting was demolded at room temperature, only minor influences on the magnitude of the resulting distortion were found.…”

Enhancing aluminum casting efficiency through real-time optical fiber sensor monitoring at the metal-mold interface

“…Improving metal manufacturing involves directly measuring mold gaps and temperature profiles during hightemperature solidification. Linear Variable Differential Transformers (LVDTs) are commonly used for precise measurements due to their linear output, high resolution, low friction, and durability [4]. However, LVDTs can be expensive, require signal conditioning, and are sensitive to environmental factors like temperature changes and magnetic fields.…”