In situ synthesis and densification of submicrometer-grained B4C–TiB2 composites by pulsed electric current sintering

Fast synthesis of B4C–TiB2 composite powders by pulsed electric current heating TiC–B mixture

“…Among these composites, B 4 C-TiB 2 ceramic was thought as one of the best potential composites that could retain the essential properties of B 4 C as much as possible. 2,[9][10][11] Firstly, TiB 2 has a higher melting point (2980 • C) than B 4 C, guaranteeing the stability of B 4 C-TiB 2 composite at high temperature. Secondary, B 4 C-TiB 2 composite is hard and light due to the high hardness (25-32 GPa) and moderate density (4.52 g cm −3 ) of TiB 2 .…”

Electrical discharge machining of B4C–TiB2 composites

“…More information on the in situ PECS synthesis is provided elsewhere. 8 Composite grades with 30, 30 in situ, 40 and 60 vol.% TiB 2 , respectively, were prepared by low energy multidirectional mixing (Turbula T2A, WAB, Switzerland) in ethanol for 24 h using ZrO 2 milling balls (φ = 5 mm).…”

“…A higher amount of grain boundaries lead to more scattering and consequently a lower thermal conductivity. 15,16 Using values from Huang et al 6,8 the average overall grain size of the commercial powder based PECS grades can be calculated for 30,40 and 60 vol.% TiB 2 PECS grades to be 1.6, 1.4 and 1.3 m, respectively. The higher amount of grain boundaries in the 40 vol.% TiB 2 PECS grade, as proven by the lower average grain size compared to the 30 vol.% TiB 2 PECS grade, leads to more phonon and electron scattering and a lower thermal conductivity, see Fig.…”

Competition between densification and microstructure development during spark plasma sintering of B4C–Eu2O3

“…High degree of covalency, low self‐diffusivity, high melting temperature and existence of surface oxide layer on nonoxide powder particles contribute to poor sinterability of boron carbide . Since the work by Skorokhod et al, there have been considerable research efforts are invested towards the use of different oxide systems as sinter additives to B 4 C . Oxide systems are thermally unstable with B 4 C and forms nonvolatile compounds (carbides/borides) in situ as reinforcement phase in ceramic matrix .…”