Translucent γ-AlOOH and γ-Al2O3 glass-ceramics using the cold sintering process

Abstract

Cold Sintering Process has been applied to hydroxide precursors Al(OH) 3 , xH O to promote in situ reactive sintering. The application of sintering temperatures < 400 °C led to the release of OH groups and partial * Corresponding author.

The effects of cold sintering parameters on the densification of Na2WO4 ceramics using Na2WO4·2H2O dry powders

“…Cold sintering process (CSP) is an innovation for the low‐temperature sintering that has developed rapidly in recent years 1–9 . It takes the advantage of mediate liquid phase with or without pressure to facilitate the densification below 300°C and now has been successfully applied in a wide variety of materials such as BaTiO 3 , SiO 2 , Al 2 O 3 and TiO 2 10–14 . Cold sintering is a complex process, involving liquid phase diffusion, arrangement of particles and interaction between liquid phase and particles 2,15–17 .…”

Phase evolution and sinterability of lanthanum phosphate – Towards a below 600 °C Spark Plasma Sintering

“…The formation of an amorphous phase as intermediate step could explain the observed lower densities measured by pycnometry. Intermediate amorphous phase formation has already been observed on other compounds such as AlOOH [19] and seems usual for phosphated compounds [31]. Mechanical properties of these samples exhibiting grain sizes < 50 nm were measured by Vickers micro-hardness and reported in Table 1.…”

“…This way, sintering process extended to new types of materials, some of which couldn't withstand high temperature sintering [13][14][15][16]. Various materials families were densified, including sulphate [17], carbonate [18], hydroxide [19], and phosphate [20].…”

“…Reactive sintering was developed for the preparation of some materials, implying a precursor decomposition (hydrated phase, hydroxide) during the sintering process to allow their densification. This was successfully applied to thermally fragile phases [17,21,22] and chemically inert materials [19,23].…”

Cold sintering of diatomaceous earth

“…The first materials produced by CSP were mainly salts and soluble compounds, 3,16 although several activities have been then carried out on ferroelectrics, 16–18 piezoelectrics, 19 magnetic ceramics, 20 semiconductors, 21–23 transparent ceramics, 24 bioceramics, 14 and ionic conductors 25–27 . More recent works regard water‐assisted cold processing of silicate ceramics including cold sintering of quartz, 28 soda‐lime silicate glass, 15 and quartz‐PTFE composite 29 or cold joining of silica 30 and cold isotactic pressing of glass monoliths 31 …”