Vol.:(0123456789) 1 3 Metals and Materials International https://doi.org/10.1007/s12540-020-00612-0 Investigation on the Effect of Stirring Process Parameters on the Dispersion of SiC Particles Inside Melting Crucible Vishal R. Mehta 1  · Mayur P. Sutaria 1 Received: 1 October 2019 / Accepted: 5 January 2020 © The Korean Institute of Metals and Materials 2020 Abstract Stirring based liquid metal processing is the widely explored process by researchers for the production of metal matrix composites (MMCs). The dispersion of reinforcement particles is the major challenge in the process. The stirring process parameters govern the dispersion of reinforcement particles in MMCs. The important stirring process parameters are stirring speed, stirrer geometry, stirrer position, and stirring time. In the literature, research works are reported, where the effect of such parameters on the dispersion of particles was investigated either by analyzing flow field using computational methods (assuming constant fluid properties) or by sectioning the casted samples. In cast condition, the dispersion of particles is also influenced by the solidification phenomena. The aim of the present work is to investigate the significance and the effect of stirrer geometry, stirrer position and stirring speed on the dispersion of reinforcement particles inside melting crucible, dur‑ ing the stirring. Aluminium alloy LM25 was used as the matrix material and silicon carbide (SiC) particles having mean size 37.58 microns (d 50 value) were used as the reinforcement phases. Samples of the composite slurry during the stirring process were dragged using a quartz tube at three levels inside crucible and microstructure analysis was carried out. Number density (ND) and inter particle distance were evaluated for parameter combinations. The uniform dispersion of SiC particles was observed at 45° stirrer blade angle, 400 rpm stirring speed and 40 mm stirrer position. And, significance order of individual parameter was observed as stirring speed < stirrer position < stirrer blade angle. Keywords Metal matrix composites (MMCs) · Stir casting · Stirrer geometry · Stirring speed · Stirrer position · Number density · Inter particle distance · Particle dispersion 1 Introduction In the last two decades, Aluminium metal matrix composites (MMCs) have sought the significant attention in automo‑ tive applications due to their advantages like lightweight (low density), high wear resistance, improved mechanical properties and low coefficient of thermal expansion [1–3]. In addition, in many cases, aluminium metal composites are economically competitive with iron and steel castings [4]. MMCs can be processed by various techniques; however, liquid processing route is the most promising preference for the production of composites due to inherent simplicity, flexibility, and frugality [5]. In this process, the matrix metal is heated to the liquid state and preheated reinforcement par‑ ticles are added and stirred. The particles get dispersed due to the continuous stirring of molten metal. The composite slurry is then poured to the mold cavity to get the desired shape. Wettability of reinforcement particle in liquid metal [6, 7], porosities in casted MMC [7–10], and selection of stirring process parameters [11] are major challenges for uniform dispersion of reinforcement particles. Many researchers have studied the effect of process parameters on the dispersion of reinforcement particles [6, 11–14]. The important parameters observed are stirring speed, stirrer geometry (blade angle), and stirring time. Singh et al. [6] have reported that for uniform dispersion of particles in casted samples, 550 rpm stirring speed, 45° blade angle stirrer and 6 min stirring time are optimal param‑ eters. Moses et al. [12] have observed that at 300 rpm stir‑ ring speed, 15 min stirring time and 30° stirrer blade angle, the tensile strength of the casted composite was maximum. * Mayur P. Sutaria mayursutaria.me@charusat.ac.in 1 Mechanical Engineering Department, Chandubhai S Patel Institute of Technology, Charotar University of Science and Technology, CHARUSAT‑Campus, Changa, Gujarat 388421, India