Recent Developments of High-Pressure Spark Plasma Sintering: An Overview of Current Applications, Challenges and Future Directions

Abstract

Spark plasma sintering (SPS), also called pulsed electric current sintering (PECS) or field-assisted sintering technique (FAST) is a technique for sintering powder under moderate uniaxial pressure (max. 0.15 GPa) and high temperature (up to 2500 °C). It has been widely used over the last few years as it can achieve full densification of ceramic or metal powders with lower sintering temperature and shorter processing time compared to conventional processes, opening up new possibilities for nanomaterials densification. More recently, new frontiers of opportunities are emerging by coupling SPS with high pressure (up to ~10 GPa). A vast exciting field of academic research is now using high-pressure SPS (HP-SPS) in order to play with various parameters of sintering, like grain growth, structural stability and chemical reactivity, allowing the full densification of metastable or hard-to-sinter materials. This review summarizes the various benefits of HP-SPS for the sintering of many classes of advanced functional materials. It presents the latest research findings on various HP-SPS technologies with particular emphasis on their associated metrologies and their main outstanding results obtained. Finally, in the last section, this review lists some perspectives regarding the current challenges and future directions in which the HP-SPS field may have great breakthroughs in the coming years.

Effect of Precursor Prehistory on the Efficiency of Radiation-Assisted Synthesis and Luminescence of YAG:Ce Ceramics

“…This conclusion is consistent for both nanopowder-based synthesis and the synthesis from larger grain sizes. It is likely that in the region with the highest absorbed energy density [14][15][16][17][18][19][20][21], the rate of new YAG phase formation is so rapid that charged particles do not have the opportunity to leave the reactor zone before the decomposition of the initial particles occurs.…”

“…Technological challenges make it difficult to optimize promising phosphors and synthesis processes, and thus research constantly focuses on improving existing technologies and developing new ones [4][5][6][7][8][9][10]. Novel methods, such as combustion [11,12] and spark plasma sintering (SPS) [13,14], have been developed to accelerate synthesis rates. However, these methods have the disadvantage of utilizing additional substances during synthesis, leading to uncontrolled amounts of remaining elements that can affect functional properties.…”

The Optimization of Radiation Synthesis Modes for YAG:Ce Ceramics

“…The thermal conductivity of the mixture for synthesis is 0.15-0.16 W/m* C, three orders of magnitude lower than in copper [19,20]. The time of passage of the irradiated section of the charge is 1 s. During this time, heat from the irradiated area does not have time to be transferred to the environment [17].…”

“…Obviously, the resulting product may contain residues of combustible substances. It is assumed that it is possible to synthesize transparent ceramic materials by the SPS method (spark plasma sintering) [17].…”

Tooling in Spark Plasma Sintering Technology: Design, Optimization, and Application

“…UHP FAST/SPS uses three types of devices adopted from the high‐pressure physics and geophysics: multianvil presses, belt‐type devices, and Bridgman‐type toroidal apparatus. [ 131 ] Anvils are the key part of all high‐pressure devices, serving as mechanical pressure multipliers. The hardness of the anvil material determines the maximal pressure in a UHP device.…”