Tough and dense boron carbide obtained by high-pressure (300 MPa) and low-temperature (1600°C) spark plasma sintering

Abstract

Dense boron carbide (above 95%) was achieved through high pressure (300 MPa) and low temperature (1600°C) Spark Plasma Sintering (SPS). This approach resulted in improvement of fracture toughness and of dynamic toughness when compared to corresponding toughness values of the sample sintered by conventional SPS (2100°C, 50 MPa). Dynamic toughness was extracted from Split Hopkinson Pressure Bar measurements. Results are understood based on microstructure and on very different behaviour of the samples in respect to residual B 2 O 3 and carbon available in the raw B 4 C powder.

High‐Temperature Strength of Boron Suboxide Ceramic Consolidated by Spark Plasma Sintering

“…correspond to the residual amorphous B–O phase resulting from the synthesis of boron suboxide powder . In general, the fracture observed at room temperature is identical to that expected for boron carbide …”

“…13,20 In general, the fracture observed at room temperature is identical to that expected for boron carbide. 25,42,43 When the testing temperature was increased to 600°C, a higher number of grain pull-outs due to intergranular fracture were observed in B 6 O-6:1. However, B 6 O-6:1 and B 6 O-10:1 still had characteristic striations on the large grains and exhibited fine cleavage fracture on the fine grains (0.4 lm).…”

High‐Strength B4C–TaB2 Eutectic Composites Obtained via In Situ by Spark Plasma Sintering

“…This is quite a high value compared with those of other diborides . In case of the monolithic boron carbide ceramics, fracture toughness not exceeding 3 MPa·m 1/2 is reported . Furthermore, toughness of B 4 C matrix in case of B 4 C–15 mol.% NbB 2 eutectic composite yielded a value of 3.3 ± 0.2 MPa·m 1/2 .…”

Dynamic failure and fracture mechanism in alumina ceramics: Experimental observations and finite element modelling

“…Composite armour composed of material layers such as ceramics, metals and adhesives has received tremendous interests due to the light weight, good shock resistance and excellent impact energy dissipation capacity [1][2][3][4][5]. The ballistic performance of composite armour is strongly dependent upon the dynamic behaviour of its layered materials, in particular the ceramics in which the strength increases with the confining pressure [3,6].…”