关键词: 脉动磁场, 缩松, 铸造原理

Abstract: Casting with pulsating electromagnetic field is a process in.Which a mould is put in a copper coil to which pulsating current is connected after pouring the liquid metal in the mould to produce a pulsating electromagnetic field which exerts pulsating electromagnetic force on the liquid metal, so that, the defects in casting are eliminated and the cast structure refined. It has been found that solidification under the pulsating electromagnetic field can completely eliminate the macroperesity and microperesity of A1-Cu5% alloy, increase the compactness of A1 alloys by 0.9% and shorten the relative intrusive depth of shrinkage cavity in pure aluminium sample from 0.56 to 0.05. The repeated washing away of the channels between dendrites in liquid-solid region under the electromagnetic force pressing metal liquid is the main factor of the eliminating of porosity, and the facilatating of the settling of grains is the reason for the shortening of intrusive depth of shrinkage cavity. The practical experiments were carried out in Harbin Steam Turbine Manufactory and Some perfect results were gained.

Key words: 脉动磁场, 缩松, 铸造原理