Livarski vestnik 52 / 2005 Nr. 4
P. Mrvar, J. Medved, M. Trbižan, A. Papež, J. Ramovš:
Nonmetallic Inclusions and Intermetal Compounds in Alloy AM60
J. Pristavec, M. Terčič:
Computer Simulation of the Thermal Loads in Aluminium Pressure Die Casting Process
P. Mrvar, J. Medved, M. Trbižan, A. Papež, J. Ramovš:
Nonmetallic Inclusions and Intermetal Compounds in
Alloy AM60
Summary
Alloy AM60
Summary
One of the main problems, connected with a recycling and also with melting, is presence of nonmetallic inclusions, presenting defects. With intention to characterise of microstructure, identification of inclusions and intermetallic compounds, definition of largeness and effect on mechanical properties the following analyses on die castings from alloy AM60 were made: chemical analysis, simultaneous thermal analysis (STA), thermodynamic calculation, determination of mechanical properties and electron microscopy. In microstructure we identified inclusions oxide, sulphide and chloride nature with energy dispersion spectrometer. Oxide inclusions are singular oxides and also bound in complex compounds Mg, Al, Si, Ca and Mo oxides. Sulphide inclusions are effect of transfer of sulphur from protecting gas into melt. They originate on base Mg, Ca, and Si. Chlorides are consequence of residue of fluxes and originate on base Mg, Na, K, Ca, and Fe. These defects act on matrix with notch factor and on that manner weaken mechanical properties.
Key words: alloy MgAl6Mn, solidification, nonmetallic inclusions and intermetallic compounds
Key words: alloy MgAl6Mn, solidification, nonmetallic inclusions and intermetallic compounds
Computer Simulation of the Thermal Loads in
Aluminium Pressure Die Casting Process
Summary
Aluminium Pressure Die Casting Process
Summary
The casting process simulation provides not only for the cavity filling visualization, determination of the solidification pattern and the evaluation of these processes through different criteria, but also analysis of the thermal happening in the tool through many successive cycles. Modelling of the complete die with heating and cooling channels within the simulation allows thermal die load monitoring during the filling and the solidification phases, as well as during the spraying and blowing of the die. The simulation results point to the areas that are under excessive heating or cooling or they are exposed to great thermal shocks. This provides for the arrangement of heating and cooling channels positions in a way that assures the adequate thermal balance in the die and thus the process stability and the long lifetime of the die. The following case presents the use of the casting simulation during the development of the die for the aluminium pressure die casting process. There are two reasons why the toolmaker decided to use the computer simulation in the die developing cycle: a short delivery time and the complexity of the die - casting dimensions are 870 x 340 x 190 mm. Because of the lack of practical experiences with the similar castings, the die design was a great new challenge to the toolmaker. The results of the simulations were of the big help in finding the right gating system and in finding the right solution to solve certain problems during the casting process. They were also efficiently used in the foundry, in finding the adequate casting parameters - the software also gives the support for the shot optimisation process.
Key words: tool construction, aluminium high pressure die casting process, thermal die loads
Key words: tool construction, aluminium high pressure die casting process, thermal die loads