Sun Kangning

Preparation and Electromagnetic Properties of an Electromagnetic Wave Absorber

In this study, we report the as-prepared MgO-doped BaFe 12 O 19 , which was prepared by calcination technique and high-energy ball milling process, as an electromagnetic wave absorber. The phase analysis of BaFe 12 O 19 and the as-prepared MgO-doped BaFe 12 O 19 was detected utilizing X-ray Diffractometer (XRD). The microstructure was characterized using Scanning Electron Microscope (SEM). By means of the transmission/reflection coaxial line method, the electromagnetic properties and microwave absorbing properties of the asprepared electromagnetic wave absorber were studied. It is found that the electromagnetic wave absorber has a minimum reflection loss value of –41 ㏈ at 4.27 ㎓ with a matching thickness of 2.6 ㎜. The experiment results revealed that the as-prepared electromagnetic wave absorber could find potential applications in many military as well as commercial industries.

The strengthening and toughening mechanism of Fe−Al/Al2O3 composite material

By means of different checks and measures, we observed and analysed the microstructure of Fe−Al/Al2O3 composite material. We found that not only intragranular nanostructure grains and rod-like crystals but also fine-grained structure of the composite material as well as the bridging of the Fe−Al intermetallics compound contribute to the materials strength and toughness. It is shown that the strengthening and toughening of the Fe−Al/Al2O3 composite is the joint effect of a multiplicate strengthening and toughening mechanism.