Citation: Kruzel, R.; Dembiczak, T.; Wachowicz, J. Optimization of Spark Plasma Sintering Technology by Taguchi Method in the Production of a Wide Range of Materials: Review. Materials 2023, 16, 5539. https:// doi.org/10.3390/ma16165539 Academic Editor: Salvatore Grasso Received: 21 June 2023 Revised: 2 August 2023 Accepted: 6 August 2023 Published: 9 August 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). materials Review Optimization of Spark Plasma Sintering Technology by Taguchi Method in the Production of a Wide Range of Materials: Review Robert Kruzel 1 , Tomasz Dembiczak 2, * and Joanna Wachowicz 3, * 1 Faculty of Civil Engineering, Czestochowa University of Technology, 3 Akademicka Street, 42-200 Czestochowa, Poland; kruzel@bud.pcz.pl 2 Faculty of Science and Technology, Jan Dlugosz University in Czestochowa, Armii Krajowej Street 13/15, 42-200 Czestochowa, Poland 3 Department of Mechanical Processing of Wood, Institute of Wood Sciences and Furniture, Warsaw University of Life Sciences, Nowoursynowska Street, 166, 02-787 Warsaw, Poland * Correspondence: t.dembiczak@ujd.edu.pl (T.D.);joanna_wachowicz@sggw.edu.pl (J.W.) Abstract: This paper reviews the production of sinters using the spark plasma sintering method. SPS (spark plasma sintering) technology has been used for several decades, mainly in laboratories, to consolidate a huge number of both new and traditional materials. However, it is now more often introduced into practical industrial use, with equipment as early as the fifth generation capable of producing larger-size components at competitive costs. Although the mechanism of sintering with the use of this method is not yet understood, the effectiveness of the SPS process for the rapid and efficient consolidation of a wide range of materials with novel micro-structures remains indisputable. With a relatively wide variation in chemical composition, the structure allows the selection of appropriate consolidation parameters for these materials. The influence on the values of apparent density and mechanical properties depends on the parameters of the spark plasma sintering process. In order to achieve a density close to the theoretical density of sinters, optimization of the sintering parameters, i.e., sintering temperature, heating rate, sintering time, pressing pressure and protective atmosphere, should be carried out. In this paper, the optimization of spark plasma sintering of Si 3 N 4 –Al 2 O 3 –ZrO 2 composite was carried out using the Taguchi method. The effects of four sintering factors, namely heating rate, sintering time, sintering temperature and sintering pressure, on the final density were investigated. Optimal sintering conditions were proposed and a confirmation experiment was conducted. The optimal combination of sintering conditions for spark plasma sintering (SPS) of Si 3 N 4 –Al 2 O 3 –ZrO 2 composite for high apparent density was determined as A3-B3-C3-D2. Based on ANOVA analysis, it was found that the apparent density of sintering was significantly influenced by sintering temperature, followed by pressing pressure, sintering time and heating rate. Validation of the developed mathematical model predicting the apparent density of sinters showed close agreement between the predicted response results and experimental results. Keywords: powder metallurgy; spark plasma sintering; optimization Taguchi method 1. Overview of the SPS Process The SPS method is used for sintering powder materials. It belongs to a broader group of current-activated methods—PECS (Pulsed Electric Current Sintering) [1–7]. This method is used for sintering various advanced composite materials (particle-reinforced, fiber-reinforced), ceramic materials (cermets, oxide and non-oxide ceramics, superhard materials), biomaterials and FGMs [8–14]. The first laboratory attempts to make a sintering device using pulses of electrical energy were carried out in the USA as early as 1933 [15–18]. In 1950, work on a method called Spark Sintering was started by Lenel [18,19]. Subsequently, leading achievements regarding the development of this technology were obtained by scientists from Lockheed Missile and Space Company in California [18,20] and Inoe from Japan [18,21,22]. Due to the Materials 2023, 16, 5539. https://doi.org/10.3390/ma16165539 https://www.mdpi.com/journal/materials