Enhanced microwave absorbing performance and corrosion resistance of FeSiBCCrx amorphous alloys

Nowadays, there is an urgent need for microwave absorbers with anticorrosion when 5G devices are extended to complex and extreme application environments such as industrial equipment and marine military. Here, a series of amorphous magnetic loss FeSiBCCrx (x = 0, 1, 1.3 and 2.2 at.%) absorbers were prepared with adjusted different Cr contents under argon atmosphere using induction melting technique and gas atomization method. The effective absorption bandwidth (EAB: bandwidth of RL < -10 dB) of FeSiBCCrx (x = 1.3) absorber at a thickness of 1.7 mm is 8.25 GHz for X and Ku-band. Meanwhile, the maximum reflection loss (RL) is -54 dB with a bandwidth of 3.09 GHz at a thickness of 3.4 mm, which can be used in the C-band. Meanwhile, the FeSiBCCrx absorbers exhibit excellent anticorrosion property with a less corrosion current density I-corr (10(-6) A cm(-2)) and increased polarization resistance R-p (10(4)-10(5) Omega). The microwave absorption (MWA) performance of FeSiBCCr1.3 remains stable under continuous neutral salt solutions corrosion for 720 h. In addition, the FeSiBCCr1.3 MWA coating exhibit excellent bifunction performance and display minimal alteration of their surface morphologies and MWA performance after the continuous salt spray test. The presented work provides a broader insight to the design of multifunctional microwave absorbing materials suitable for harsh environments.