Abstract: A sample composed of a nickel-based metal is immersed in a corrosive solution (aqueous solution containing an acid and sodium chloride). The sample that has been immersed in the corrosive solution is exposed to a flame of engine oil, and further heated. By immersing the sample in the particular corrosive solution, a Ni-enriched phase which is deficient in additional elements and in which the Ni concentration increases is formed in a surface layer region of the sample. By exposing the sample having the Ni-enriched phase to the flame of the engine oil, components in the engine oil are activated and brought into contact with the sample to form a low-melting point phase in the surface layer region of the sample. By heating the sample having the low-melting point phase to melt the low-melting point phase and resolidifying the low-melting point phase, particles and the like can be formed depending on the type of material of the sample.

Abstract: A sample composed of a nickel-based metal is immersed in a corrosive solution (aqueous solution containing an acid and sodium chloride). The sample that has been immersed in the corrosive solution is exposed to a flame of engine oil, and further heated. By immersing the sample in the particular corrosive solution, a Ni-enriched phase which is deficient in additional elements and in which the Ni concentration increases is formed in a surface layer region of the sample. By exposing the sample having the Ni-enriched phase to the flame of the engine oil, components in the engine oil are activated and brought into contact with the sample to form a low-melting point phase in the surface layer region of the sample. By heating the sample having the low-melting point phase to melt the low-melting point phase and resolidifying the low-melting point phase, particles and the like can be formed depending on the type of material of the sample.

Abstract: An oxide film is formed on the surface of a sample made from a metal material by holding the above-described sample at a temperature of 800° C. or higher and 1,100° C. or lower in an oxygen-containing atmosphere, and the sample provided with the oxide film is immersed in a corrosive solution containing an acid and NaCl for a predetermined time. After immersion, the corrosion state (degree of denseness of oxide film, cracking state, and the like) of the sample is evaluated. The corrosion resistance of the sample can be evaluated appropriately and conveniently in a short period of time by causing accelerated corrosion in an environment simulating the actual environment of an internal combustion engine.

Abstract: An electrode material contains, on a mass percent basis, Al: 0.005% to 0.2%, Si: 0.2% to 1.6%, Cr: 0.05% to 1.0%, Ti: 0.05% to 0.5%, and Y: 0.2% to 1.0%. The remainder are Ni and inevitable impurities. The Si/Cr mass ratio is 1 or more. Because of the inclusion of specific amounts of Al, Si, Cr, and Y and the Si content higher than the Al content, the electrode material has an oxidation inhibiting effect. The inclusion of the specific amount of Ti can reduce the occurrence of expansion and cracking of the oxide film. Because of the inclusion of the specific amount of Y, the oxide film can maintain the microstructure even at high temperatures and have high resistance to high-temperature oxidation. Having a Si/Cr ratio of 1 or more, the oxide film has improved corrosion resistance and is resistant to corrosion by corrosive liquids.

Abstract: A metal structure according to the present invention is unlikely to become brittle and has excellent hardness and creep resistance, characterized in that annealing has been applied at a temperature not more than the temperature at which crystals of the metal material start to become larger. This metal structure includes at least two kinds of metal material, and annealing can be applied at a temperature not more than the temperature at which crystals of the metal material start to become larger. For example, the present invention is advantageous in the manner of a microstructure for a contact probe. A fabricating method according to the present invention is a method of fabricating a metal structure unlikely to become brittle and having excellent hardness and creep resistance, characterized in that the step of applying annealing at a temperature not more than the temperature at which crystals of the metal material start to become larger is included.

Abstract: A metal structure according to the present invention is unlikely to become brittle and has excellent hardness and creep resistance, characterized in that annealing has been applied at a temperature not more than the temperature at which crystals of the metal material start to become larger. This metal structure includes at least two kinds of metal material, and annealing can be applied at a temperature not more than the temperature at which crystals of the metal material start to become larger. For example, the present invention is advantageous in the manner of a microstructure for a contact probe. A fabricating method according to the present invention is a method of fabricating a metal structure unlikely to become brittle and having excellent hardness and creep resistance, characterized in that the step of applying annealing at a temperature not more than the temperature at which crystals of the metal material start to become larger is included.

Abstract: A metal structure according to the present invention is unlikely to become brittle and has excellent hardness and creep resistance, characterized in that annealing has been applied at a temperature not more than the temperature at which crystals of the metal material start to become larger. This metal structure includes at least two kinds of metal material, and annealing can be applied at a temperature not more than the temperature at which crystals of the metal material start to become larger. For example, the present invention is advantageous in the manner of a microstructure for a contact probe. A fabricating method according to the present invention is a method of fabricating a metal structure unlikely to become brittle and having excellent hardness and creep resistance, characterized in that the step of applying annealing at at a temperature not more than the temperature at which crystals of the metal material start to become larger is included.