Citation: Szyma ´ nski, P.; Popielarski, P.; Czarnecka-Komorowska, D.; Sika, R.; Gawdzi ´ nska, K. Determination of Saturation Conditions of the Aluminum Metal Matrix Composites Reinforced with Al 2 O 3 Sinter. Materials 2023, 16, 6106. https:// doi.org/10.3390/ma16186106 Academic Editor: Tomasz Sadowski Received: 11 August 2023 Revised: 29 August 2023 Accepted: 4 September 2023 Published: 7 September 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 Article Determination of Saturation Conditions of the Aluminum Metal Matrix Composites Reinforced with Al 2 O 3 Sinter Pawel Szyma ´ nski 1 , Pawel Popielarski 1 , Dorota Czarnecka-Komorowska 1 , Robert Sika 1, * and Katarzyna Gawdzi ´ nska 2 1 Institute of Materials Technology, Poznan University of Technology, Piotrowo 3 Str., 61-138 Poznan, Poland; pawel.szymanski@put.poznan.pl (P.S.);pawel.popielarski@put.poznan.pl (P.P.); dorota.czarnecka-komorowska@put.poznan.pl (D.C.-K.) 2 Faculty of Marine Engineering, Maritime University of Szczecin, Willowa 2-4, 71-650 Szczecin, Poland; k.gawdzinska@pm.szczecin.pl * Correspondence: robert.sika@put.poznan.pl Abstract: Aluminum metal matrix composites (Al MMCs) are a class of materials characterized by being light in weight and high hardness. Due to these properties, Al MMCs have various applications in the automobile, aeronautical and marine industries. Ceramic-reinforced Al MMCs in the form of sinters are known for having excellent abrasive properties, which makes them an attractive material in certain fields of technology. The biggest problem in their production process is their low ability to infiltrate ceramics with alloys and consequently the difficulty of filling a ceramic preform. The castability of such composites has not yet been researched in detail. The aim of this study was to create aluminum metal matrix composite castings based on aluminum alloys (AlSi11) reinforced with an Al 2 O 3 sinter preform using a Castability Trials spiral mold, and then to determine the degree of saturation with the liquid metal of the produced ceramic shaped body (Castability Trials spiral). For the selected AlSi11 alloy, the liquidus (Tl) and solidus (Ts) temperatures were determined by performing thermal-derivation analysis during cooling, which is Tl—579.3 ◦ C and Ts—573.9 ◦ C. The resultant pressure necessary for the infiltration process was estimated for the reinforcement capillaries with the following dimensions: 10, 15, 20, 25, 30 and 35 microns. The following values were used to determine the capillary pressure (Pk): surface tension of the alloy—σ = 840 mN/m; the extreme wetting angle of the reinforcement by the metal—θ = 136 ◦ . It has been experimentally confirmed that for the vacuum saturation process, the estimated resultant pressure enables saturation of reinforcement with capillaries larger than 25 microns, provided that the alloy temperature does not drop lower than the infiltration temperature. After the experiment, the time and route of the liquid metal flow in the spiral were determined. On the basis of the obtained values, a simulation was developed and initial assumptions such as saturation time, alloy temperature, reinforcement and mold temperature were verified. The energy balance showed that the saturation limit temperature was Tk = 580.7 ◦ C for the reinforcement temperature of 575 ◦ C. In contrast to the above, the assumption that the temperature of the metal after equalizing the temperature of the composite components must be higher than the liquidus temperature (Tliq = 579.3 ◦ C) for the aluminum alloy used must be fulfilled. After the experiment, the time and path of the liquid metal flow in the spiral were determined. Then, on the basis of the obtained values, a simulation was developed, and the initial assumptions (saturation time and temperature) were verified. Keywords: casting; aluminum metal matrix composites; castability; energy balance 1. Introduction The casting properties of an aluminum alloy have a significant impact on the mold- filling process, and they have an influence on the structure and properties of the casting, especially of the composite casting, where a reinforcing phase appears. One of the most Materials 2023, 16, 6106. https://doi.org/10.3390/ma16186106 https://www.mdpi.com/journal/materials