| 摘要 |
PURPOSE:To lower the pack treating temp., in formation of a diffusion-coated layer of Al on the surface of an article by pack cementation, by using pack powder consisting of a specified amt. of Al-Cu alloy power contg. a restricted amt. of Cu, a halide and an inert carrier to facilitate diffusion of Al. CONSTITUTION:In formation of a diffusion-coated layer of Al on the surface of an article by pack cementation, pack powder of the following compsn. is used: 5-40% Cu-contg. Al-Cu alloy powder 5-40%, a halide such as NH4Cl 0.5-5% and an inert carrier such as alumina the balance. By this method the pack treating temp. required to obtain a predetermined pack layer thickness can be made lower than that of a conventional method. The practical pack temp. necessary to an effective thickness is 750-800 deg.C, and it is equal to or lower than the final aging temp. of a Ni alloy for a gas turbine blade material. Accordingly, the properties of base metal are slightly deteriorated by pack treatment. |
