Investigation of spherisation in microstructures of aluminium casting alloys for thixoforging process


GÜLER K. A. , GECÜ R. , KISASÖZ A. , KARAASLAN A.

RUSSIAN JOURNAL OF NON-FERROUS METALS, cilt.58, ss.489-494, 2017 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 58 Konu: 5
  • Basım Tarihi: 2017
  • Doi Numarası: 10.3103/s1067821217050066
  • Dergi Adı: RUSSIAN JOURNAL OF NON-FERROUS METALS
  • Sayfa Sayıları: ss.489-494

Özet

Thixoforging combined with low superheat casting (LSC) is a promising shaping process for aluminium casting alloys. LSC process is based on rapid solidification of an alloy which cast with low pouring temperature. With this method, a feedstock material is produced with non-dendritic microstructure that ready for spherisation in reheating sequence of further semi-solid process. Al-Si alloys are still castable even at low temperatures due to their excellent fluidities. This study subjects to present spherisation of A356 and A380 alloy billets cast with LSC process that provides appropriate beginning material with relatively high sphericity. Obtained billet parts were reheated for different times at a semi-solid state temperature. Some of these billets were directly quenched for observing the effects of reheating and the others were thixoforged. With sufficient reheating time, deformation of thixoforging process did not significantly affect on the spherical microstructure. Unnecessarily long reheating period caused excessive grain growth. A356 alloy had higher spherisation tendency than A380 alloy under similar process conditions.