Structure Evolution between Closely Located Microchannels Produced by Ni-Al Sacrificial-Core Method

摘要

The structures between closely located microchannels having Ni-Al intermetallic lining layers have been investigated. The microchannels were produced by a sacrificial-core method using nickel as the body metal which composes the device body and aluminum as the sacrificial-core metal which gives the shape of the microchannel. Three basic types of interaction of the microchannels were detected: isolation (no interference), coalescence of the lining layers, and coalescence of the microchannels. In a particular case when the two lining layers just touched each other, a coarse void defect formed near the tangent point. The formation mechanism of the void defect was successfully explained in terms of the unbalanced diffusion of aluminum and nickel in Ni-Al intermetallic compounds.