Effects of Solidification Techniques on Cast Quality: A Systematic Review and Network Mapping

Development of suitable solidification techniques in casting can eradicate segregation/ defects and achieve an equiaxed grain structure. This work systematically reviews 65 research articles on the principles of solidification in casting and the commonly studied solidification techniques namely directional, progressive and rapid solidification and inoculation treatments. The effects of various solidification process parameters on the mechanical and microstructural properties are outlined. A keyword co-occurrence network analysis is developed to visualize the predominantly researched areas and future research directions in solidification domain. Key findings include (i) Directional solidification (DS) is predominantly studied in turbine blade fabrication and single crystal growth. Fabrications of porous dental/bio-medical implants using DS, the effect of inoculation treatment in DS cast and study of DS of ternary alloys in multi-shell mould casting are gaining momentum. (ii) Self inoculation method under rheo-die casting is most studied especially in ductile cast iron and Al alloys. The dendrite arm spacing and segregation under inoculation treatment with Ti, B, Co and Si as primary/ secondary inoculant are much researched. (iii) The applications of progressive solidification in cryopreservation, in Metal matrix ceramic composites fabricated by stir casting and in inoculation treatment to eradicate hot tearing susceptibility need attention. (iv) Under rapid solidification (RS) domain, the formation of bimodal microstructure using RS coupled with heat treatment, fabrication of metallic glass structures using RS through planar flow casting and eradication of center-carbon segregation and achieving carbon homogeneity need attention.