2022 年 7 巻 p. 110-116
A Ni-Al sacrificial-core method is a powder metallurgical process to directly produce a microchannel and a Ni-Al intermetallic alloy layer lining the microchannel wall in a nickel body. Aluminum wire was used for the sacrificial-core metal which gave the shape of the microchannel. Influence of the initial porosity of the nickel powder compact on the formation of cracks and their self-healing behavior near the lining layer has been investigated. When the initial porosity Ε0 was 28.7%, both clacks and healed regions, in which molten aluminum infiltrated and filled the cracks, were observed. When the initial porosity was lower (Ε0 = 23.3%), a continuous, large-sized healed region was observed and there were no clacks. In the case of higher porosity (Ε0 = 36.2%), only the healed regions had extended in a circumferential direction of the microchannel.
