Abstract
A simple and economical fabricating process for free-form microchannels in metal bodies has been proposed. The concept for our process is based on a microscopic infiltration phenomenon that often occurs during liquid phase sintering of a mixture of different metals powder, e.g., a mixture of titanium and aluminum. In our microchanneling process, a shaped compound of aluminum powder and an organic binder is used as a sacrificial core. The powder-binder compound is formed into the same shape as the intended microchannel-network by a micro-injection process. A titanium powder compact containing the sacrificial core is sintered at a temperature above the melting point of aluminum. During sintering of the powder compact, the organic binder is removed and liquid aluminum originating from the aluminum powder flows into narrow capillaries between the titanium powder particles and reacts with the titanium particles to produce Ti-Al alloy layers lining the cavity formed at the sites initially occupied by the powder-binder compound. The composition, phase and structure of the lining layers can be changed by the addition of a third element into the powder-binder compound.
