Electromagnetic Physical Field Of Al-5wt% Cu Alloy Solidification Process And The Solidification Microstructure

In this article, Al-Si alloy and Al-5wt%Cu alloy are served as investigated object imposed rotating electromagnetic field (REMF) and pulse current. Al-5wt5%Cu is been as studying keystone .The experimention indicates:Comparing to sample structure in single REMF and single pulse current, alloy structure is smaller in the compound field (REMF + pulse). Axis crystal grains take on evidently, and have arranged in order.The rotating magnetic field function produced electromagnetism force, and make alloy fluid flow round axis at column sample surface layer, and pulse electromagnetism reinforce the electromagnetism force, spurring system flow as three dimension. The first, this force strengthen scour force to solidification branch crystal, and make branch crystal break. The second, this effect make melting alloy temperature uniformity, which cause breaking off, dissociative crystal preserving at the volley. This is in favor of forming axis crystal.the pulse current can change alloy solidification structure and crystal temperature, and different pulse current parameter lending to different result. But the generic direction change from branch crystal to plum blossom crystal, axis crystal and puncheon crystal. At the same time, we find having better current parameter affect alloy solidification better.In the directional solidification condition, the current not only changed columnar crystal size, appearance, crystal space, but also changed columnar crystal tropism. The current also changed clearly branch crystal size, appearance, crystal space.In this article, we discussed the mechanism.In the processing of the directional solidification in pulse current operation, the introducing of energy and substance is a opening system. The processing of solidification keeps away from balance state. The introducing of energy and substance induce structural gurgitation, leading to self-structure dissipation. With different disturbing frequency, solid-liquid interface take on diversity, and behave non-linear. Because compelled once branch space is one of the foremost characters of the solidification structure. It is good for studying.These experiment results showed that imposed physics filed could have special effect to solidification processing and structure of alloys. It could become a new method for controlling solidification. This is worthy of continuing study.