Bimodal transparent alumina ceramics prepared with micro/nano-particles under high pressure

Sintering dense boron carbide without grain growth under high pressure

“…One possible way to overcome the obstacles might be applying an ultrahigh pressure during the sintering. The ultrahigh pressure was valid to suppress the grain growth and further increase the density and mechanical properties in studies of structural ceramics such as Al 2 O 3 13 and SiC. 27 In the present work, fully dense B 4 C without grain growth is successfully fabricated under ultrahigh isostatic pressure (3.5-5.0 GPa) in a cubic press.…”

“…13,28 The raw powder was first loaded into a mould and pressed into disc shape using a cold press method. High pressure and temperature were performed using a cubic-type multi-anvil apparatus (YL-800t, Guilin Guiye Heavy Industries Co. Ltd., China).…”

“…Thus, the two competing mechanisms of densification and grain growth always coexist in sintering. [11][12][13] Structural ceramics are becoming increasingly relevant for harsh processing environment applications. In recent years, extensive efforts have been made to improve density while limiting the grain growth.…”

“…However, in order to reach the greatest possible density, the increase in the processing temperature would reactivate the grain growth. The ultrahigh pressure was valid to suppress the grain growth and further increase the density and mechanical properties in studies of structural ceramics such as Al 2 O 3 13 and SiC. Recently, ultrahigh pressure has been developed and used for phase transformation of materials (e.g., diamond and cubic boron nitride) 9,10 and also preparing the transparent ceramics.…”

“…Recently, ultrahigh pressure has been developed and used for phase transformation of materials (e.g., diamond and cubic boron nitride) 9,10 and also preparing the transparent ceramics. [11][12][13] Structural ceramics are becoming increasingly relevant for harsh processing environment applications. In particular, boron carbide (B 4 C) has attracted a lot of attention owing to its high hardness, low density, high-melting point, good thermal stability, extreme abrasion resistance and chemical inertness, as well as its high neutron absorption cross section.…”