Reaction‐bonded B₄C/SiC composites synthesized by microwave heating

Abstract

The reaction‐bonding technique was used to synthesize boron carbide (B4C) ‐ silicon carbide (SiC) composites by microwave heating. Preforms of porous B4C were obtained by compaction followed or not by partial densification. Then, the material was infiltrated by molten silicon under a microwave heating. The influence of the thermal cycles (T: 1400‐1500°C, t: 5‐120 minutes) is low. The hardness of boron carbide is comparable to that of alumina (15‐19 GPa) for a much lower density (≈2.5 g/cm3 for B4C‐based material instead of 3.95 g/cm3 for alumina). These properties make this composite, obtained by microwave heating, a good candidate for ballistic applications.

Investigation of Microstructural Features and Mechanical Characteristics of the Pressureless Sintered B4C/C(Graphite) Composites and the B4C-SiC-Si Composites Fabricated by the Silicon Infiltration Process

“…The EDS spectroscopic analysis depicted that the silicon infiltrated composites were composed primarily of boron, silicon, and carbon, thereby demonstrating that the composites obtained following silicon infiltration comprised boron carbide and silicon carbide along with some content of silicon. It can therefore be assumed that the liquid silicon infiltrated into the interior of the composite and produce silicon carbide upon reaction with boron carbide, according to the following reaction equations [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ]: 5 Si + 3 B 4 C = 3 SiC + 2 SiB 6 2 Si + B 4 C = SiC + SiB 4 …”

“…Because the pressureless sintered B 4 C/C(graphite) composites have a porosity of about 25–38%, the liquid silicon could be conveniently infiltrated into the interior of the composites [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ], subsequently reacting with B 4 C and graphite to produce the silicon carbide [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. While the boron carbide reacted only partially [ 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ], the graphite reacted completely with silicon producing silicon carbide [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ]. The residual boron carbide and silicon existed within the matrix of the composite [ 40 , 41 , 42 , 43 , 44 , 45 , 46 <...…”

“…While the boron carbide reacted only partially [ 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ], the graphite reacted completely with silicon producing silicon carbide [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ]. The residual boron carbide and silicon existed within the matrix of the composite [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ] and together with silicon carbide gave rise to the B 4 C-SiC-Si composites [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ]. The pressureless sintered B 4 C/C(graphite) composites are thus transformed into the B 4 C-SiC-Si composites via the silicon infiltration process [ 40 ,…”

“…The residual boron carbide and silicon existed within the matrix of the composite [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ] and together with silicon carbide gave rise to the B 4 C-SiC-Si composites [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ]. The pressureless sintered B 4 C/C(graphite) composites are thus transformed into the B 4 C-SiC-Si composites via the silicon infiltration process [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ]. The microstructural details, phase composition, and mechanical characteristics of the B 4 C/C(graphite) composites as well as B 4 C-SiC-Si composites fabricated by the silicon infiltration process were then investigated and compared.…”

Optimization of the decarbonizing ratio of boron carbide powders by reverse flotation using response surface methodology

“…Therefore, it has been widely used in the grinding of hard materials, the manufacture of lightweight and super hard materials and the nuclear industry. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Currently, the main method for preparing B 4 C is carbothermal reduction.…”