Journal of Materials Science & Technology 43 (2020) 189–196 Contents lists available at ScienceDirect Journal of Materials Science & Technology journal homepage: www.jmst.org Formation of spherical alloy microparticles in a porous salt medium Hayk H. Nersisyan a , Suk Cheol Kwon b , Vladislav E. Ri b , Wan Bae Kim b , Woo Seok Choi b , Jong Hyeon Lee a,b,∗ a RASOM, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Republic of Korea b Graduate School of Materials Science and Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Republic of Korea a r t i c l e i n f o Article history: Received 2 August 2019 Received in revised form 1 October 2019 Accepted 22 October 2019 Available online 8 January 2020 Keywords: AlSi12 alloy Morphology evaluation Particle distribution Simulation Solid-liquid transition Spheroidization a b s t r a c t This study describes the development of a one-pot strategy to produce spherical alloy microparticles for advanced near-net-shape manufacturing processes, including additive manufacturing and powder injection molding. The AlSi12 eutectic alloy (ca. 12 wt% Si) system was chosen as the model with which the main experiments were carried out. The proposed process synergistically integrates a few common, low-cost processing techniques including the mixing of Al micrometer size particles with silicon and sodium chloride, heat-treating the mixture at temperatures of 650–810 ◦ C, and the dissolution of salt in water to produce spherical AlSi12 alloy particles without the need to rely on costly melting and atomizing techniques. This new process can use laow-cost source Al and Si powders as the raw materials to produce 10–200 m-sized spherical particles of AlSi12. The Ansys-CFX computational fluid dynamics software was used to analyze the flow behavior of AlSi12 liquid droplets and particle size refinement in the narrow voids of the sample. © 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology. 1. Introduction Spherical particles have drawn considerable attention in recent years for their novel applications. Owing to the uniform size of spheres coupled with good flowability, applications of spher- ical particles include additive manufacturing for the medical, aerospace, jewelry, and automotive industries [1–3]. Therefore, the size and spherical shape of particles are critical factors in determin- ing material properties, and the ability to control these properties in synthesis processes has become a major goal in the field of materials science [4–10]. As of this writing, atomization is the main synthe- sis technique that has been reported for the synthesis of spherical particles. The following types of atomization processes are known: water atomization [11,12], gas atomization [3–18], soluble gas or vacuum atomization [19], centrifugal atomization [20–22], the ultra-rapid solidification process [23], and ultrasonic atomization [24,25]. In conventional (gas or water) atomization, liquid metal is produced by pouring molten metal through a tundish with a nozzle at its base. The stream of liquid metal is then broken into droplets ∗ Corresponding author at: Graduate School of Materials Science and Engineering, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Republic of Korea. E-mail address: jonglee@cnu.ac.kr (J.H. Lee). by the impingement of high-pressure gas or water. The interaction between the liquid metal stream and the jets begins with the cre- ation of small disturbances at the liquid surface, which grow into shearing forces that fragment the liquid into ligaments. The broken ligaments are further formed into spherical particles due to the high energy of the impacting jet. Like all powder processing applications, atomization methods are potentially sensitive to several powder characteristics that relate to the method in which the material was atomized. The atomization issues that affect key powder charac- teristics include alloy melting techniques, atomization media and collection, and process costs. This is why the atomization process does not always yield spherical and dense particles, and many irreg- ularities (such as satellites) are formed by the interaction of molten particles during solidification. A simple and widely applicable method of synthesizing a vari- ety of spherical particles in large quantities would help in exploiting the potential of such particles and pave the way for a new field in spherical particle-based science. Recently, the synthesis of ultrafine metal particles from metal (powder)-graphite (graphene) mixtures was reported in Refs. [26,27]. After being heat-treated at 1000 ◦ C, the reaction mass is quenched to room temperature and exposed to ultrasonic treatment to separate the spherical particles from the graphite. The shortcoming of the reported method is the contami- nation of metals by free and chemically bonded carbon. Skalon et al. [28] reported a new production method for spherical aluminum https://doi.org/10.1016/j.jmst.2019.10.029 1005-0302/© 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.