The Influence of In-Cavity Pressure on Heat Transfer and Porosity Formation During High-Pressure Die Casting of A380 All
- PDF / 962,119 Bytes
- 8 Pages / 593.972 x 792 pts Page_size
- 47 Downloads / 197 Views
https://doi.org/10.1007/s11837-020-04341-y Ó 2020 The Minerals, Metals & Materials Society
ALUMINUM AND MAGNESIUM: CASTING TECHNOLOGY AND SOLIDIFICATION
The Influence of In-Cavity Pressure on Heat Transfer and Porosity Formation During High-Pressure Die Casting of A380 Alloy M.S. DARGUSCH ,1,4 A. HAMASAIID,1,2,3 G. DOUR,2 N. BALASUBRAMANI,1 and D.H. STJOHN1 1.—School of Mechanical and Mining Engineering, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia. 2.—IMT Albi-Carmaux, Institut Cle´ment Ader. ICA-Albi, Route de Teillet, 81 013 Albi Cedex 09, France. 3.—3DmetDie, 118, 20 Chemin de la Teulie`re, 81000 Albi, France. 4.—e-mail: [email protected]
This paper is concerned with the measurement of thermal properties and incavity pressures in cold chamber high-pressure die casting. The influence of in-cavity pressure on the casting porosity, heat flux, and heat transfer coefficient has been investigated during die casting of an A380 alloy. The die was instrumented with heat transfer and pressure sensors to measure these values directly. Direct measurement of the in-cavity pressure was found to be more reliable than the metal pressure calculated from pressure measurements in the hydraulic system. Variations on the intensification pressure directly affect the in-cavity pressure. Changing the intensification pressure between 17 MPa and 90 MPa had little effect on the heat flux and heat transfer which likely reach saturation at a lower pressure during the rapid filling stages. Increases in intensification pressure reduced the level of porosity within the castings, being most effective up to a value of 67.4 MPa.
INTRODUCTION Radio frequency (RF) filter bodies, gearboxes, transmission cases, and cam covers are examples of components suitable for production using highpressure die casting (HPDC).1 This range of lightweight aluminium structural parts are ideal candidates for HPDC,2 because this casting method is highly suitable for the production of components with a good surface finish in reasonable volumes. The mechanisms of heat transfer during the process control both the life and the condition of the die and part quality.3,4 Dies being used in HPDC are generally made of tool steels of type 1.2344 (AISI H13) or 1.2343 (AISI H11). These types of tool steels are used for their dimensional stability and high mechanical strength at elevated temperatures along with good toughness and resistance to thermal shock and thermomechanical fatigue.
(Received June 17, 2020; accepted August 17, 2020)
Good thermal balance within the die can only be maintained with a sound understanding of processing and its relationship with productivity while reducing the thermal stresses within the tool.3 Over time, these thermal stresses result in heat checking and deterioration in the quality of the die surface. This in turn results in deterioration in the surface quality of the part and shortens its lifespan. In the case of RF filter bodies, this results in a dramatic decrease in the performance of the part. It is importa
Data Loading...
