Investigation on the effect of Fe impurity pickups during ball milling and Ni dispersion on the microwave absorption performance of ball milled Fe impurities-Ni/SiC composites

The development of microwave absorbers to mitigate the problem of electromagnetic pollution has become a necessity in today's electronic era owing to the rapid growth in the electronic industries covering every sphere of human life from civilian to the defense and medical sectors. The requirement of microwave absorbers having desirable characteristics such as strong absorption, wide absorption bandwidth, thin absorber thickness along with the low cost is still a huge challenge. Thus, the present work focuses on the development of ball milled Fe impurities-Ni/SiC microwave absorbing composites using a very simple and cost-effective ball milling route. The present work investigates the influence of Fe impurity pick-ups from the steel balls during the ball milling operation and Ni concentration on the microwave absorption characteristics of milled Fe impurities-Ni/SiC composites. The ball milled Ni/SiC composites with Fe impurities exhibited a strong microwave absorption response in the Ku band compared to pure and ball milled SiC counterparts. Ball milled Fe impurities-Ni/SiC composites with 3 wt% Ni concentration exhibited superior microwave absorption characteristics. The corresponding value of maximum microwave absorption represented by the minimum reflection loss (RL) value was calculated to be - 17.82 dB at an absorber thickness of 2.4 mm. The concerned sample also exhibited a wide broadband frequency response (corresponding to < - 10 dB) of 5.51 GHz at the same absorber thickness. The improved microwave absorption characteristics for the milled Fe impurities-Ni/SiC composites make it a promising candidate for applications in the Ku band.