High-pressure die casting (HPDC) plays an increasingly important role in the automotive industry as electric cars become more universal. The more complex casting geometries face increasing challenges to the foundries and the casting users. The local squeezing process aims to eliminate the hot spot i.e. the place of potential formation of shrinkage porosity. Local squeezing is a unique technique that is applied as a part of the HPDC process and is an essential tool for scrap reduction. During local squeezing, the squeeze pin is activated when the mold filling of the die cavity is finished, and the melt begins to solidify. The timing of the operation of the squeeze pin is a crucial factor. Applying the correct timing ensures that the crystallization process will result in a proper microstructure and mechanical properties meeting the requirements. The timing of the squeeze pin affects its displacement. The later the pin is started, the more resistance it encounters during compaction and the shorter the stroke it can make in the cavity during solidification. It was experimentally demonstrated that increasing the delay time of the squeeze pin from 0.1 sec to 0.8 sec and reducing the speed of movement from 5 mm/s to 1 mm/s results in 2-4 % in porosity level and 20-50 % improvements in tensile strength.
Author
(s) Details
Viktor
Nyeste
University of Miskolc, Institute of Physical Metallurgy,
Metalforming and Nanotechnology, 3515 Miskolc-Egyetemváros, Hungary.
Tamás
Mikó
University of Miskolc, Institute of Physical Metallurgy,
Metalforming and Nanotechnology, 3515 Miskolc-Egyetemváros, Hungary.
Dániel
Molnár
University of Miskolc, Institute of Chemical Metallurgy and
Foundry Engineering, 3515 Miskolc-Egyetemváros, Hungary.
Valéria
Mertinger
University of Miskolc, Institute of Physical Metallurgy,
Metalforming and Nanotechnology, 3515 Miskolc-Egyetemváros, Hungary.
Please see the book here:- https://doi.org/10.9734/bpi/mono/978-93-49473-95-9/CH8
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