All issues › Volume 1, Issue 1, July – August 2026
Process Parameter Control in Stir Casting of Aluminium Matrix Composites: A Review of Wettability, Particle Distribution and Porosity Mechanisms
Department of Mechanical Engineering, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai, Tamil Nadu, India
Abstract
Stir casting remains the dominant liquid-state route for the manufacture of particulate-reinforced aluminium matrix composites (AMCs), principally because it accommodates large batch sizes, tolerates a wide range of reinforcement chemistries and imposes the lowest capital burden among competing routes. Its persistent limitation is reproducibility: the same nominal composition, processed on different equipment or by different operators, frequently yields divergent microstructures and consequently divergent properties. This review argues that the reproducibility problem is not attributable to any single parameter but to the fact that the governing parameters act on three distinct and partially antagonistic physical mechanisms — wettability at the particle–melt interface, hydrodynamic transport and dispersion within the vortex, and gas entrainment leading to porosity. A parameter setting that improves one mechanism frequently degrades another, and the optimum is therefore a compromise rather than a maximum. The review organises the literature around this three-mechanism framework rather than around parameters considered in isolation. Stirring speed, stirring duration, impeller geometry and immersion depth, melt superheat and processing temperature regime, particle preheating and feed rate, wettability modification through magnesium addition and halide salt fluxing, and atmosphere control are each examined for their mechanistic action and their trade-offs. Characteristic defect morphologies — clustering, settling and pushing segregation, interfacial reaction products and gas porosity — are related back to the parameter combinations that produce them. The optimisation literature, dominated by Taguchi and response surface designs, is assessed critically: the review finds that the prevalence of single-response optimisation and the near-universal omission of melt-temperature-history reporting together account for much of the inter-study inconsistency in reported optima. Five research gaps are identified, of which the absence of standardised distribution-quantification metrics and of validated coupled thermal–hydrodynamic–particle models are judged the most consequential.
Keywords: stir casting, aluminium matrix composites, process parameters, wettability, particle distribution, porosity, metal matrix composites
How to cite
Ravi, M. (2026). Process Parameter Control in Stir Casting of Aluminium Matrix Composites: A Review of Wettability, Particle Distribution and Porosity Mechanisms. Imaginex International Journal of Interdisciplinary Research and Reviews, 1(1), 11–18.