A microwave absorbing material with soft magnetic nanoparticles based on negative refraction loss characteristics

摘要

Nano aluminum/titanium oxide spraying process was explored and the mechanical properties were studied. Atmosphere plasma spraying method was used for preparing aluminum/titanium oxide ceramic coating with nano structure, and fixing spraying current, spraying distance and powder feeder rotation speed. Four groups of hot spraying specimens with different processes were prepared by adjusting the main air pressure and spraying voltage, which optimized the preparation process. The bonding strength, microstructure, hardness, fracture toughness, cupping property and thermal shock resistance after optimization were represented, and the friction and wear performances of nano ceramic coating in the ball disc mode were also represented. The optimal nano ceramic coating was AT13, which was determined by the microstructure hardness, crack resistance and fracture toughness data of coating. Nano ceramic coating had higher bonding strength and hardness, and nano tissue of original powder inherited excellent cupping resistance of nano coating, so the toughness is obviously better than that of traditional micron coating. After water quenching cycle test at 400 degrees C for 50 times, the coating did not lose efficacy at all. In the ball disc friction wear under high load, the wear extent of nano ceramic coating is low, and the friction coefficient is stable, which shows good wear resistance. Nano aluminum oxide ceramic coating has high bonding strength, excellent cupping performance, wear resistance, good comprehensive mechanical properties, so it could be used for rigid working environment.