▎ 摘　　要

NOVELTY - Preparing polycarbosilane/zirconia laser protective composite coating involves providing surface sequentially with bonding layer, zirconium oxide coating and polycarbosilane coating. The base material NiCrCoAlYHf bonding layer is made and sandpaper is used to grind the surface of the aluminum alloy with size of 25millimeterx 2 millimeter and model of 2A12 to roughness. The 2A12 aluminum alloy is made of 0.00-0.50 wt.% silicon, 0.30-0.90 wt.% manganese, 0.00-0.30 wt.% zinc, 1.2-1.8 wt.% magnesium, 0.00-0.15 wt.% titanium, 3.80-4.90 wt.% copper, 0.00-0.50 wt.% aluminum alloy smelted with iron, 0.00-0.10 wt.% nickel, 0.00-0.50% iron and nickel and balance is aluminum. The roughened aluminum alloy is washed with acetone and deionized water for 3-5 times, and dried in vacuum blast oven at 15-80 degrees C for 1-5 hours to obtain clean aluminum alloy base material. USE - Method for preparing polycarbosilane/zirconia laser protective composite coating. ADVANTAGE - The method has good laser protection effect, high temperature resistant, good light reflectivity, heat conducting ability, strong scattering loss, relieves heat stress, improves heat resistance of paint film, and achieves better laser protection effect. DETAILED DESCRIPTION - Preparing polycarbosilane/zirconia laser protective composite coating involves providing surface sequentially with bonding layer, zirconium oxide coating and polycarbosilane coating. The base material NiCrCoAlYHf bonding layer is made and sandpaper is used to grind the surface of the aluminum alloy with size of 25millimeterx 2 millimeter and model of 2A12 to roughness. The 2A12 aluminum alloy is made of 0.00-0.50 wt.% silicon, 0.30-0.90 wt.% manganese, 0.00-0.30 wt.% zinc, 1.2-1.8 wt.% magnesium, 0.00-0.15 wt.% titanium, 3.80-4.90 wt.% copper, 0.00-0.50 wt.% aluminum alloy smelted with iron, 0.00-0.10 wt.% nickel, 0.00-0.50% iron and nickel and balance is aluminum. The roughened aluminum alloy is washed with acetone and deionized water for 3-5 times, and dried in vacuum blast oven at 15-80 degrees C for 1-5 hours to obtain clean aluminum alloy base material. The 55.00-65.00 pts. wt. nickel, 16.00-22.00 pts. wt. chromium, 10.00-14.00 pts. wt. cobalt, 8.00-10.00 pts. wt. aluminum, 0.20-0.70 pts. wt. yttrium and 0.05-0.30 pts. wt. hafnium, mixed uniformly to obtain NiCrCoAlYHf powder with particle size of 40-106 micrometer, and then applied powder to the above-mentioned aluminum alloy base material by plasma spraying. The current during plasma spraying is 300-900A, main gas is high-purity argon gas with flow rate of 20-80L/minute, secondary gas is hydrogen gas with flow rate of 2-15L/minute, spraying distance is 50-200 millimeter, powder is transported. The thickness of the bonding layer is controlled to be 50-200 micrometer, and aluminum alloy material with NiCrCoAlYHf bonding layer is prepared. The intermediate zirconia coating is prepared by mixing 65-75 pts. wt. zirconium dioxide with particle size of 10-50 micrometer, 10-15 pts. wt. ytterbium oxide with particle size of 10-50 micrometer, 2-8 pts. wt. yttrium oxide with particle size of 10-50 micrometer and 8-12 pts. wt. cerium oxide with particle size of 10-50 micrometer uniformly. The mixed powder is srayed on the NiCrCoAlYHf bonding layer of the aluminum alloy material by plasma spraying. The current during plasma spraying is 300-900A, main gas is high-purity argon gas with flow rate of 20-80L/minute, secondary gas is high-purity hydrogen gas with flow rate of 2-15L/minute, and spraying distance is 50-200 millimeter, powder transmission rate is 10-60g/minute, thickness of the zirconium oxide coating is controlled to be 80-300 micromete. The aluminum alloy material is prepared with zirconia coating and NiCrCoAlYHf bonding layer. The top polycarbosilane coating is prepared first. The 35-45 pts. wt. polycarbosilane, 25-35 pts. wt. divinylbenzene and 5-10 pts. wt. dicumyl peroxide are added at room temperature, magnetic stirred at speed for 10-30 minutes. The mixture is placed into 30-90 degrees C water bath and continued to stir magnetically at speed of 400-800 revolution/minute for 30-120 minutes. The 8-16 pts. wt. graphene powder is added with thin layer thickness of 0.5-2.0 nanometer and specific surface area of 2630 m2/g and 1-2 pts. wt. polyethylene is added with molecular weight of 200-8000. The poly(ethylene glycol) is used as dispersant, continued to stir for 10-60 minutes to obtain polycarbosilane coating. The polycarbosilane is roll-coated with thickness of 50-300 micrometer on the basis of the zirconium oxide coating obtained and placed in constant temperature blast oven at 140-160 degrees C for heat treatment for 1-3 hours and then cooled to room temperature. The target polycarbosilane/zirconia laser protective composite coating is obtained.