Tungsten disulfide modified bismaleimide
AssigneeAlliedSignal Inc.
InventorsJimmy C.-H. Chan, Betty H. Kocsis
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Abstract
A method of restoring a damaged surface of a metal substrate to a functional conditions through application of a filler material consisting essentially of bismaleimide and tungsten disulfide having a ratio of 10:1. The bismaleimide having been cured through the following sequence to maintain the durability thereof when exposed to aromatic fuels at temperatures up to 500.degree. F., the temperature of the bismaleimide is uniformly raised from room temperature to 350.degree. F. in one hour and maintained at 350.degree. F. for an additional hour and thereafter the temperature is immediately raised to 475.degree. F. and maintained at 475.degree. F. for an additional two hours.
Claims3
A method of restoring a damaged and/or worn surface on a metal substrate to substantially conform with an original surface profile, said method comprising the steps of:
- mixing a filler material consisting essentially of tungsten disulfide and bismaleimide together to obtain a uniform mixture;
- applying a quantity of filler material on said damaged and/or worn surface;
- placing said metal substrate in an oven;
- uniformly raising the temperature of said oven and said metal substrate to define a cure cycle for said bismaleimide, said cure cycle including:
- a one hour ramp from room temperature to a cure temperature of 350.degree. F.;
- a one hour maintenance period at a temperature of 350.degree. F.;
- and a post cure of two hours at a temperature of 475.degree. F., said cure cycle providing good surface wetting of said substrate and a gradual release of any volatiles in said filler material while allowing cross linking of said bismaleimide in said filler material without significant porosity thereof;
- and
- machining any excess cured material from said damaged and/or worn surface to re-establish said original surface profile.
Dependencies are inferred from the claim text.