Mold Filling Analysis in Lost Foam Casting Process for Aluminum Alloys and Its Experimental Validation

Abstract

A mathematical model is developed in this study to simulate the filling pattern in lost foam casting and validated by comparing the simulated results to the experimental measurements. A special treatment is devised to handle the unique problem of back-pressure generated due to the evaporation of polystyrene during filling in lost foam casting. Experiments are also conducted with thermocouples embedded in the pattern of lost foam casting. With the measured temperature data, filling pattern can be derived. The mathematical model is then tested on several lost foam castings, where experimental measurements are also conducted. As the simulated filling patterns are compared with the experimental measurements, good agreement is observed.

Simulation of EPS foam decomposition in the lost foam casting process

“…Mirbagheri et al [6] used empirical pressure equation to correct the free surface pressure originated from the application of the VOF method [3]. By forcing the tangential stress at the metal front to vanish and normal stress to balance the externally exerted normal stress, Kuo et al [7] applied back pressure force in the momentum equation and used several trials to determine a proper back-pressure for the model to get agreement results with experimental data. In the current modeling study with FLOW-3D, a correction factor caused by the gas pressure at the metal front is introduced, as follows…”

“…Mirbagheri et al [6] developed a foam degradation model with a pressure correction scheme for the free surface at the metal front based on the SOLA-VOF technique. A similar backpressure force scheme was adopted by Kuo et al [7] in the momentum equation and the value of this force was adjusted to study the filling sequence of patterns according to experimental results.…”

Mold-filling and Solidification Simulation of Grey Iron in Lost-Foam Casting

“…Moreover, the Bernoulli equation method [9] , limiting interface frontier speed method [5] , and backpressure amendment method [10] and other methods [11] to approximately simulate the status of LFC filling process were emerged among these research results. In this paper, we put forward a kind of mathematical models which in line with the disappearance of molded alloy filling characteristics based on the foregoing summary and research the results of the researchers, and applied to the numerical simulation program.…”

A finite element model for the simulation of lost foam casting

“…Update boundary condition for the temperature on mf and mo Solve Heat equation (11) 4 , multiplying the contribution of the front elements by 10…”

“…This approach has the advantage that it naturally takes into account the back-pressure e ects due to the decomposition of the EPS pattern. A possible implementation is explained in Reference [4]; this method however does not consider the heat transfer rate between metal and foam as explicit part of the front advance mechanism. See also Reference [5], where the authors propose in addition a model for the back-pressure.…”