Abstract: A separator is provided with a substrate portion having a predetermined concave-convex shape, an underlying coating layer formed on the substrate portion, a first coating layer coating the substrate portion and the underlying coating layer, and a second coating layer formed thereon. The second coating layer, which is formed from carbon materials, is sufficiently electrically conductive and protects the underlying layers. The first coating layer is formed from a low-melting-point metal subjected to a melting process. The melting process is a process of first conducting heating at such a temperature that melts the low-melting-point metal but does not melt the substrate portion and the underlying coating layer and then conducting cooling. Thus, in the first coating layer, the crystal grain size of the metal is increased and thus the grain boundary density is reduced.

Abstract: A separator is provided with a substrate portion having a predetermined concave-convex shape, an underlying coating layer formed on the substrate portion, a first coating layer coating the substrate portion and the underlying coating layer, and a second coating layer formed thereon. The second coating layer, which is formed from carbon materials, is sufficiently electrically conductive and protects the underlying layers. The first coating layer is formed from a low-melting-point metal subjected to a melting process. The melting process is a process of first conducting heating at such a temperature that melts the low-melting-point metal but does not melt the substrate portion and the underlying coating layer and then conducting cooling. Thus, in the first coating layer, the crystal grain size of the metal is increased and thus the grain boundary density is reduced.

Abstract: A separator is provided with a substrate portion having a predetermined concave-convex shape, an underlying coating layer formed on the substrate portion, a first coating layer coating the substrate portion and the underlying coating layer, and a second coating layer formed thereon. The second coating layer, which is formed from carbon materials, is sufficiently electrically conductive and protects the underlying layers. The first coating layer is formed from a low-melting-point metal subjected to a melting process. The melting process is a process of first conducting heating at such a temperature that melts the low-melting-point metal but does not melt the substrate portion and the underlying coating layer and then conducting cooling. Thus, in the first coating layer, the crystal grain size of the metal is increased and thus the grain boundary density is reduced.

Abstract: The present invention provides a fuel cell separator which is capable of maintaining a low and stable contact resistance at a state of an oxidizing water vapor atmosphere for a long time. The separator 20 has a separator base 22 facing electrodes 14, 16, and there are a plurality of projections 24 on a surface of the separator base 22. AS the projections 24, a Sn—Bi alloy, a Sn—Bi alloy containing Ag or the like are preferable. The separator is produced by adhering a molten bath 32, composed of a Sn alloy, to the separator base 22, then pressing a die 34 with numerous small-holes 34a against the molten bath 32, and then pouring the molten bath 32 into a cavity formed by the base 22 and small-holes 34a.

Abstract: A separator is provided with a substrate portion having a predetermined concave-convex shape, an underlying coating layer formed on the substrate portion, a first coating layer coating the substrate portion and the underlying coating layer, and a second coating layer formed thereon. The second coating layer, which is formed from carbon materials, is sufficiently electrically conductive and protects the underlying layers. The first coating layer is formed from a low-melting-point metal subjected to a melting process. The melting process is a process of first conducting heating at such a temperature that melts the low-melting-point metal but does not melt the substrate portion and the underlying coating layer and then conducting cooling. Thus, in the first coating layer, the crystal grain size of the metal is increased and thus the grain boundary density is reduced.

Abstract: A aluminum alloy in the form of bulk includes an aluminum matrix and carbon particles having an average particle size of 100 nm or less and dispersed in the aluminum matrix in an amount of 1 to 40 atomic % with respect to the total atoms constituting the aluminum alloy. The aluminum alloy is produced by preparing a raw material comprising aluminum and carbon as components and forming an aluminum alloy by inserting the raw material into a cavity formed by a set of dies and applying repeatedly plastic deformation to the raw material while maintaining the temperature of the raw material in the range of from 100 to 400.degree. C.

Abstract: A process for producing an aluminum alloy in the form of mass includes: preparing as a material to be formed a mixed powder of aluminum and at least one kind of metal or non-metallic substance selected from the elements belonging to Groups 4a, 4b, 5a, 6a, 7a and 8a of the periodic table and boron, or a compact or a cast material formed of the mixed powder; placing the material to be formed in a die, and performing plastic deformation repeatedly on the material to be formed at 100.degree. to 400.degree. in an inert atmosphere while retaining at least part of the material to be formed in a confined state, so as to cause diffusion reaction between phases constituting the material to be formed, thereby forming the quasi-stable phase composed mainly of amorphous phases and/or supersaturated solid solution phases.