Method for repairing damage on non-friction surface of carbon brake disc of aircraft

A method for repairing damage on a non-friction surface of a carbon brake disc of an aircraft, comprising the following steps:

• step 1):
• removing a damaged region comprising:
• visually inspecting the damaged region on the non-friction surface of the carbon brake disc, determining a damage removal area, and marking the damage removal area, wherein the damage removal area is wider than an edge of the damaged region, the damage removal area is round or elliptical, and a maximum removal depth is a maximum depth of the damaged region;
• after the damage removal area is marked, polishing the damage removal area into a slope shape by using a polishing tool to obtain a polished damaged carbon brake disc;
• machining first glue-flowing grooves on a polished surface of the polished carbon brake disc;
• placing the polished damaged carbon brake disc in an ultrasonic cleaner for cleaning, and then transferring the polished damaged carbon brake disc into a vacuum drying oven for drying;
• step 2):
• cutting of a repair material comprising:
• obtaining the repair material with a volume larger than the damage removal area by cutting a scrap carbon brake disc;
• polishing the repair material until the repair material is sized to the damage removal area;
• machining second glue-flowing grooves on a bonding surface of the repair material;
• placing the repair material after being polished in the ultrasonic cleaner for cleaning, and then transferring the repair material into the vacuum drying oven for drying;
• step 3):
• anti-oxidation modification of the repair material comprising:
• step 3.1):
• mixing and stirring evenly Al2O3, B2O3, TiO2 and ZrB2 powders to obtain mixed powders;
• step 3.2):
• adding lithium tetraborate to a sodium silicate aqueous solution to obtain a first solution, and stirring the first solution to obtain a stable solution;
• then adding the mixed powders obtained in step 3.1) into the stable solution to obtain a second solution, and stirring the second solution to obtain a modifying solution;
• step 3.3):
• pouring the modifying solution obtained in step 3.2) into an impregnating tank, completely submerging the repair material in the modifying solution, and then vacuumizing the impregnating tank to vacuum impregnate the modifying solution into the repair material and obtain an impregnated repair material;
• and step 3.4):
• drying the impregnated repair material, and then curing the impregnated repair material in an oven at 80-120° C. for 2-4 h;
• step 4):
• bonding and curing comprising:
• applying an adhesive to the polished surface of the polished carbon brake disc and the bonding surface of the impregnated repair material, and bonding the impregnated repair material to the polished surface;
• clamping the polished carbon brake disc and the impregnated repair material by using a clamp, and removing a spilled excess of the adhesive;
• putting the polished carbon brake disc with the impregnated repair material into the oven for curing to form a bonded carbon brake disc;
• then removing a vacuum bag from the bonded carbon brake disc after curing, and polishing and smoothing a repair zone of the bonded carbon brake disc to obtain a smoothed carbon brake disc;
• and
• step 5):
• heat treatment comprising:
• placing the smoothed carbon brake disc obtained in step 4) into a pre-vacuumized pyrolysis furnace and filling the pyrolysis furnace with N2 and heating to perform a heat preservation, and then cooling the smoothed carbon brake disc to room temperature within the pyrolysis furnace to obtain a repaired carbon brake disc.