초록 ▼

The instant invention describes a method of repairing heat-resistant alloy parts which have been cracked or otherwise damaged due to exposure of combustion gases from a turbojet engine. The method includes chemically cleaning the surface of the part to remove the layer of contaminants and subjecting

The instant invention describes a method of repairing heat-resistant alloy parts which have been cracked or otherwise damaged due to exposure of combustion gases from a turbojet engine. The method includes chemically cleaning the surface of the part to remove the layer of contaminants and subjecting the part to a thermochemical treatment to thoroughly clean the cracks and other narrow, damaged areas. A diffusion brazing process is then utilized to fill the cracks or damaged areas.

대표청구항 ▼

A method for repairing cracked or damaged parts made of a heat resistant nickel, cobalt based alloy having a surface with a contaminated layer of chemical compounds comprising the steps of: (a) chemically cleaning the surface of the part, said chemical cleaning comprising the steps of: (i) de-scalin

A method for repairing cracked or damaged parts made of a heat resistant nickel, cobalt based alloy having a surface with a contaminated layer of chemical compounds comprising the steps of: (a) chemically cleaning the surface of the part, said chemical cleaning comprising the steps of: (i) de-scaling the part; (ii) rinsing in water bath; (iii) immersing the part in an alkaline bath to convert oxides on the part into soluble elements; (iv) rinsing in water bath; (v) immersing the part in acid pickling bath comprising an aqueous solution of hydrochloric acid, nitric acid, acetic acid, phosphoric acid and a ferric salt to remove the converted oxides; and (vi) rinsing in water bath; (b) thermochemically treating the part to clean the cracks and damaged areas of the part by placing it in a semi-permeable enclosure in a hydrogen controlled atmosphere oven and heating it with reaction components to transform the oxides remaining on the part; (c) depositing a filler metal on the surface and the visible damaged areas of the part, the filler metal being an alloy having at least nickel or cobalt and including a filler element to render the filler metal easily meltable and capable of diffusing into the part; (d) subjecting the part to a first thermal brazing cycle to fuse the metal filler and wet the surfaces to which it is applied; (e) depositing a mixture of a base powder and a filler powder on the surface of the part having visible defects, the base powder containing substantially no filler element and the filler powder containing at least nickel or cobalt with a filler element to render it more easily meltable than the alloy of the part and the base powder; (f) subjecting the part to a second thermal brazing cycle to thoroughly alloy the powder mixture and to wet the surface to which it is applied; and, (g) subjecting the part to thermal diffusion treatment for a time and at a temperature to insure homogenization of the repaired zone.