Sustainable processing is required

Sustainable processing is required to aid societal needs in reducing CO2 emissions and lowering manufacturing costs; therefore, a protocol to produce high-quality ceramics through sintering at low temperatures and in shorter times is of significant interest. The cold sintering process (CSP) has been introduced as a non-equilibrium sintering approach that can densify ceramics at extraordinarily low temperatures (T=300℃) and has been successful on over 70 inorganic materials[1]. The benefit of low-temperature sintering also has led to a process strategy to develop new materials, such as the co-sintering of composite materials made up of ceramics and polymers, and nanocomposites with two-dimensional materials in grain boundaries (GBs)[2]. Both the densification and grain growth kinetics of CSP are significantly accelerated relative to conventional sintering of equivalent materials, and zinc oxide (ZnO) is used as a model example, as there is extensive data on its use in fundamental sintering studies.However, underlying mechanisms in CSP are unknown, and revealing these mechanisms will provide further understanding and aid in the selection of the transient phases better enabling CSP.