A Study on Al/Cu Bimetal Production by Lost Foam Casting


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

PRAKTISCHE METALLOGRAPHIE-PRACTICAL METALLOGRAPHY, cilt.55, sa.11, ss.728-740, 2018 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 55 Konu: 11
  • Basım Tarihi: 2018
  • Doi Numarası: 10.3139/147.110523
  • Dergi Adı: PRAKTISCHE METALLOGRAPHIE-PRACTICAL METALLOGRAPHY
  • Sayfa Sayıları: ss.728-740

Özet

A356 aluminium alloy/commercially pure (CP) copper bimetal was produced via liquid-solid process by lost foam casting (LFC) technique. Cu rod was placed into an expanded polystyrene (EPS) pattern followed by applying thermoplastic adhesive to cover apertures between rod and foam, pattern coating, drying and moulding in a steel flask using free silica sand. Molten A356 alloy was poured into moulded pattern at 760 degrees C and 790 degrees C, respectively. Also, hot dip A356 coating was implemented on Cu rods for each casting temperature and the effect of pre-coating on the final product was studied. Optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) and hardness devices were used to determine microstructural evaluation and interface features. No metallurgical bonding occurred between Al and both coated and uncoated Cu rods at 760 degrees C. However, better mechanical bonding was observed comparing to uncoated sample cast at 790 degrees C because Cu rod surface was started to deteriorate with increasing casting temperature. Under favour of hot dip coating, uniform and continuous interface was obtained at 790 degrees C. theta-Al2Cu and eta(2)-AlCu formations were determined at the interface according to XRD and EDS results. Interface hardnesses were measured as 422 HV0.01 for theta-Al2Cu and 697 HV0.01 for eta(2)-AlCu phases.