B4C and Al2O3 Microwave sintering for armour application – BAMBi

Powder metallurgy is a mean of obtaining metallic, ceramic or composite materials appropriate with the current economical and environmental issues (raw materials and energy saving). Microwave sintering improves powder metallurgy competitiveness by leading to sample densification in very short times and with low energy consumption. This very fast densification opens new prospects for obtaining finer microstructures. To sum up, this process improves the functional as well as the structural properties of materials.
In this context, the Bambi project is focused on microwave sintering of two important materials used for ballistic applications : alumina and boron carbide.
One of the challenge in this project is to use the microwave heating specificities in order to densify alumina with the finest microstructure, ideally nanostructured.

Concerning boron carbide, the challenge is to study its behaviour under microwave irradiations and then to explore its densification. The addition of a mechanical energy, such as a uniaxial pressure, is also considered in this project. This study must lead to a better understanding and knowledge of this strategic material for defence applications.

A lot of innovative points are associated with these two challenges. For examples the research of microwave experimental conditions in monomod and multimode cavity, which are necessary for the control of nanostructure alumina, as well as microwave sintering at very high temperature (> 2000°C) with possibly the addition of a mechanical pressure.

The microwave heating process development could bring crucial technological advancement to civil and military domains and could lead to applications in high temperature materials processing (synthesis, sintering, annealing diffusion).