Effect of Temperature on the Microwave-Absorbing Properties of an Al2O3–MoSi2 Coating Mixed with Copper

Abstract

To obtain a high temperature-resistant microwave absorbing coating, an Al2O3–MoSi2/Cu composite coating was prepared by atmospheric plasma spraying. Compared with a normal temperature environment, there are a few reports on Cu as an absorbent for high temperature microwave absorbing coatings. Therefore, in this regard, wave absorbing property can be improved by using a Cu absorbent. The microstructure of a Al2O3–MoSi2/Cu coating was observed, and the dielectric properties of the composite coating in the high-temperature environment of the X-band were tested. The experimental results show that with the increase in temperature, Cu transforms Cu2O in the high-temperature environment and improves the coating’s wave absorption performance with MoSi2. In addition, a 1.4 mm-thick coating showed best microwave absorbing performance at 700 °C. The reflection loss was −19.09 dB, and the effective microwave absorbing bandwidth was 2.83 GHz (Reflection Loss < −10 dB). It was found that the Al2O3–MoSi2/Cu composite coating has good wave-absorbing performance in a 700 °C high-temperature environment.

High temperature microwave absorbing materials

“…Gao et al fabricated Al 2 O 3 -MoSi 2 /Cu composites through the atmospheric plasma spraying method. 101 Moreover, the reaction of copper with oxygen could form CuO or Cu 2 O, which improved the high-temperature absorbing performance. The EAB and minimum RL of composites were À19.09 dB and 2.83 GHz at 700 1C, respectively.…”

Low Reflection-Loss Thermal Barrier Coating on Hastelloy C276 for Radio Control Rocket Tip Nosecone Using Yttria-Stabilized Zirconia (YSZ) at Extreme Temperature

“…In addition to mechanical performance, it is also necessary to know about the emission of waves of YSZ coating material to transmit waves from the control room to the telemetry of the rocket must have a low reflection loss (RL). On the nosecone rocket, the value of RL>-10 is because if it is below -10, the material can absorb the waves [11].…”