New numerical techniques to quantify and predict the effect of entrainment defects, applied to high pressure die casting

Q Science > QC Physics

Watson, Robert ; Griffiths, William D

University:University of Birmingham

Department:School of Metallurgy and Materials

关键词: Q Science;    QC Physics;   

Others  :  http://etheses.bham.ac.uk//id/eprint/7153/1/Watson16PhD.pdf

来源: University of Birmingham eTheses Repository

【 摘 要 】

High Pressure Die Casting (HPDC) is an attractive option for automotive manufacturers, as it has a number of advantages over wrought process routes. An improved understanding of the defects which may result from the process could allow castings to deliver lighter vehicle structures. A novel algorithm was developed to predict the formation of entrainment defects, which may limit the strength of castings. This model was integrated into FLOW-3D, a fluid dynamics solver. Theoretical advances were made, which offer a means of extrapolating a spatial distribution of damage to location specific statistical distributions, an improved way of characterising the contribution of each defect type to strength, and a means of correlating parameters for statistical distributions, allowing the variation in strength may be predicted at arbitrary locations within a casting. Casting and numerical experiments were performed, to evaluate these algorithms and underlying fluid flow solution, and to test the influence of entrainment defects on the strength of HPDC parts. Defects formed by air entrainment were found to significantly limit the strength of the studied castings. The methods and techniques explored in this work showed promise, but further advances would be needed, before ab intio strength prediction for HPDC parts can be realised.