| 摘要 |
PURPOSE:To uniform the layer and to control the position of the layer accurately, when forming a layer for controlling the diffusion of the reducing agent in the substrate metal by forming a high density deposition belt of inner oxide particles in the substrate metal thereby mainly controlling the diffusion of the reducing agent. CONSTITUTION:A substrate metal 32 is thermally treated for 20min under the temperature of 1,000 deg.C in the oxidizing environment or in the mixed gas of CO and CO2 (mixing ratio of 1:10) to produce a dispersion layer of the reducing agent oxide particles 36 in the proximity of the surface of the substrate metal 32, then CO gas is increased to lower the pressure of oxygen and when heating higher than said temperature a layer 38 where the reducing agent oxide particles are deposited with high density is formed in the proximity of the surface in the substrate metal. Said layer 38 will control the diffusion of the reducing agent located further inner than said layer from diffusing to the surface and function to produce good effect for the emission of electron. The figure shows the relation between the time for heating Ni alloy containing 0.1wt% of Mg in the oxidizing environment and the position of the layer 38. |
