document: From this study where a commercial Al–12Si alloy was inoculated with different level of Nb+B addition to assess the grain refining potency of Nb+B inoculation it can be concluded that in-situ formed Nb-based intermetallics compounds are potent heterogeneous nucleation substrates with high potency for the refinement of Al–Si cast alloys. The primary α-Al dendritic grain size varies with the addition level of Nb and B. Moreover, significant grain refinement over a wide range of cooling rates is obtained via enhanced heterogeneous nucleation making the grain size of the material less sensitive to the cooling rate. Nb+B inoculants are characterised by some fading which is still acceptable after 4 h of contact time. Moreover, alloys refined by means of Nb+B inoculants can be recycled obtaining a fine grain structure with small addition or no further addition of inoculants after the first initial addition. Concluding, Nb+B inoculation is a promising candidate for the refinement of cast Al alloy which could lead to their wider employment in the automotive industry with the resultant intrinsic advantages of lighter structural component from an environmental point of view.
extractive_keyphrases: al–12si alloy alloys b cast al alloy enhanced heterogeneous nucleation fading fine grain structure grain heterogeneous nucleation substrates inoculants lighter structural component nb wide range of cooling rates
abstractive_keyphrases: al–si cast alloys grain refinement grain refining potency of nb+b inoculation inoculated with different level of nb+b nb+b nb-based intermetallics compounds nb+b inoculants nb+b inoculation refinement of al–si cast alloys refinement of cast al alloy α-al dendritic grain