Al₂O₃–B₄C–Al Composite Material Systems via Pressureless Infiltration Methods

Abstract

Modification of the Al2O3–Al system's chemistry via the addition of B4C is described and is shown to result in fully dense structures via wetting techniques at high temperatures, without the need for pressure‐assisted infiltration. The relationships between the surface area of boron carbide and alumina powders, the effectiveness of infiltration, the material chemistry following infiltration, and the resulting mechanical properties of Al2O3–B4C–Al composites are evaluated. Additional approaches, including the incorporation of aluminum metal powder as an additional wetting agent before infiltration, are described in conjunction with a variation of both the surface areas and the volumetric ratios of inert Al2O3 to reactive B4C phases. These methods can provide the means to achieve low‐cost metal matrix composites in both vacuum and argon infiltration environments, and represent an approach that enables the generation of articles with complex geometries, requiring minimal secondary finishing treatment.

Synthesis of B4C, Al2O3, and AlB12 reinforced Al matrix nano composites via mechanochemical method

“…When the time of milling was increased over 2 h, enough mechanical energy provided the required chemical activity and causes T ig to be lower than the local temperature, so Reaction (1) would happen. Consequently, a lot of energy was released due to an exothermic reaction, and mechanical activation provided chemical activation leading to AlB 12…”

“…4,11 Recently, a pressure less infiltration method has been investigated which is used for the synthesis of Al 2 O 3 -B 4 C-Al composites. 12 In this study, synthesis of the metal matrix nanocomposite powder Al/B 4 C-AlB 12 -Al 2 O 3 was carried out via a mechanochemical method by using Al-B 2 O 3 -C as precursor materials at room temperature. Then, the mechanical properties of the fabricated composite from the synthesized powders were studied.…”

Interfacial Microstructure in a B4C/Al Composite Fabricated by Pressureless Infiltration

“…[9][10][11][12][13][14] Because B 4 C is very reactive with molten Al [15] and thus it meets the required wetting condition, it is feasible to use the pressureless infiltration method to prepare the B 4 C/Al MMCs. [16][17][18][19][20][21] In the literature, as compared with other systems like SiC/Al, the information is limited concerning the B 4 C/ Al MMCs. Viala et al systematically studied the chemical reactivity of B 4 C with Al.…”