초록 ▼

A method for cleaning metal parts, particularly crack damaged gamma prime hardened nickel alloy parts, but also including stainless steels superalloys, and solid solution superalloys in order to render them brazable or otherwise bondable. The method makes use of a C-O-H-F atmosphere as the primary c

A method for cleaning metal parts, particularly crack damaged gamma prime hardened nickel alloy parts, but also including stainless steels superalloys, and solid solution superalloys in order to render them brazable or otherwise bondable. The method makes use of a C-O-H-F atmosphere as the primary cleaning material wherein the atmosphere has an H/O ratio of 104 or greater, and a C/F ratio of approximately 0.01 to less than 2.0. The preferred source of the C-O-H-F atmosphere is thermal decomposition of a fluorocarbon resin and a low moisture containing hydrogen gas although sources other than fluorocarbon resins are also disclosed.

대표청구항 ▼

A method for cleaning unbrazable metal parts to render them brazable or otherwise bondable which comprises: (a) placing said part in a hermetically sealed chamber, (b) subjecting said part to a gaseous atmosphere, said atmosphere containing the elements C, O, H and F and having an H/O ratio of 104 o

A method for cleaning unbrazable metal parts to render them brazable or otherwise bondable which comprises: (a) placing said part in a hermetically sealed chamber, (b) subjecting said part to a gaseous atmosphere, said atmosphere containing the elements C, O, H and F and having an H/O ratio of 104 or greater and a C/F ratio of about 0.01 to less than 2.0, (c) raising the temperature of said chamber to a temperature less than 800°C. and establishing a F/H ratio in said atmosphere at which passivating oxides on the surface of said part are converted to fluorides, (d) raising the temperature of said chamber above the temperature employed in step (c) to a temperature less than 1000°C. and diluting said atmosphere with additional hydrogen to destabilize CrF3 on the surface to elemental chromium, (e) cooling said chamber and said part.