اندازه گيري فاصله هوايي ايجاد شده در فصل مشترك قطعه ريختگي -قالب فلزي در ريخته گري ثقلي آلياژ Al-12%=Si به روش الكتريكي خازني

Measurement of Air-Gap Produced at Interface of Casting-Metallic Mold in Gravity Casting Al-12%Si Alloy by Electrical Capacity Method

In this research the Air-Gap interface cast-metallic mold is determined using the electrical-capacity method. In this method the internal surface of mold and the outer surface of the cast is considered as capacitor plates and the Air-Gap between them is considered as capacitor dielectric and the Air-Gap thickness and the rate of change it with respect to time is obtained by a mathematical model. In this study the formation of the Air-Gap in cylindrical specimen of Al-l2%Si Alloy in a low-carbon steel mold and in the gravity casting is investigated. The cylindrical specimen is 80 millimetres in diameter and 150 millimetres in height and the thickness of mold is 30 millimetres. In order to charging the electricity on the capacitor plates, electrical potential difference between the plates of