Effect of the boron content in the aluminium/boron composite

Aluminium/boron metal–matrix composites (MMC) were fabricated and tested changing the boron content (10–50 wt.%) and using powder isostatic compaction and sintering as consolidation method. This high boron material can be used in nuclear applications, where boron gives neutron absorption properties, but not as structural material. The main objective was to study the influence of temperature on the reactivity of boron and aluminium and on the formation of new phases. By means of Differential Thermal Analysis (DTA), the formation of new phases was studied as well as sintering temperature was determined, finding that temperature was dependent on the boron content. Materials were characterized through density and mechanical properties (bending strength and hardness tests) finding, as expected, changes in properties with boron content. Furthermore, microstructural and fractographic studies have been performed by means of Scanning Electron Microscopy (SEM). Sintering process of these materials promoted the formation of borides, thus, X-ray diffraction (XRD) study was carried out in order to identify which kind of borides were formed.