Sintering and Reactive Sintering by Spark Plasma Sintering (SPS)

Abstract

A wide variety of technological applications, especially in electronics, requires high-density nanostructured solids, consolidated by sintering from nanoparticles. A new sintering technique known as spark plasma sintering (SPS) appears as the only method to reach high densities while preserving the final grain size within the nanometric range, with the added advantage of carrying out the process at significantly lower temperatures and shorter times as compared with the classical processes. Recent studies have revealed that in many cases, SPS can also accomplish the solid-state reaction to achieve the desired compound, leading to reactive SPS (RSPS). In this chapter, a review of RSPS is presented, focusing particularly on magnetic oxide materials as functional solids.

Effect of Reactive SPS on the Microstructure and Properties of a Dual-Phase Ni-Al Intermetallic Compound and Ni-Al-TiB2 Composite

“…The size and irregular shape of this phase indicate the occurrence of high temperature in this area during the sintering process (as a result of microspark discharges in the gap between adjacent powder particles). This possibility was pointed out many times by other researchers [47][48][49], and also in publications on reactive SPS [50][51][52].…”

Spark Plasma Sintering of Titanium Aluminides: A Progress Review on Processing, Structure-Property Relations, Alloy Development and Challenges

“…Therefore, at temperatures above 600 • C, reactions between the graphite covered tools and the O present in the sample may occur. Excess O, as stated by Franceschin et al [73], can arise from the gaseous sintering atmosphere or moisture. The vigorous gaseous transportation occurring between the sample and the graphite mold may encourage the precipitation of C or carbides [55].…”

“…For this reason, caution should be taken when selecting tooling materials. Pressing tools are generally covered with graphite foils/sheets to ease sample removal subsequent to SPS [73,74]. Therefore, at temperatures above 600 • C, reactions between the graphite covered tools and the O present in the sample may occur.…”

Synthesis of YB2C2 by high‐energy ball milling and reactive spark plasma sintering

“…Reactions (4) and (5) occurred most probably due to the effects of pressure and electrical current during SPS. G. Franceschin et al 38 reported that the generation of electrical discharges during SPS induced a significant reduction of impurity phases in siliceous compounds. The application of pressure during densification has been reported to affect the phase formation in the sintered specimens.…”