Iron-rich　intermetallic　compound　Sm2Fe17N3　is　considered　to　be　a　highly　promising　candidate　for　new-generation　permanent　magnetic　materials.　Here,　the　Ti-substituted　Sm2(Fe,　Ti)17N3　alloys　were　synthesized　using　reduction-diffusion　and　nitridation.　The　microstructure　and　magnetic　properties　of　Sm2(Fe,　Ti)17　and　its　nitrides,　in　relation　to　the　effect　of　Ti　substitution,　were　systematically　investigated　through　a　comprehensive　experimental　approach　combined　with　first-principles　calculations.　It　was　revealed　that　the　Ti　substitution　is　very　effective　in　particle　refinement　of　Sm2(Fe,　Ti)17.　The　Rietveld　analysis　of　X-ray　data　demonstrated　an　expansion　in　the　unit　cell　volume　of　Sm2(Fe,　Ti)17　phase　with　increasing　Ti　content.　Subsequent　nitridation　experiments　highlighted　the　beneficial　impact　of　an　appropriate　Ti　addition　on　the　enhancement　of　both　coercivity　and　remanence　in　Sm2(Fe,　Ti)17N3　magnetic　powder.　The　highest　coercivity　of　8.9　kOe　was　achieved　in　the　sample　with　a　Ti/Fe　mole　ratio　of　0.04.　Furthermore,　the　possible　crystallographic　occupancy　of　Ti　and　its　effect　on　the　phase　stability　are　investigated　using　first-principles　calculations.　Our　results　indicated　that　the　phase　stability　is　influenced　by　the　synergistic　effect　of　Ti　substitution　atoms　and　interstitial　N　atoms.　The　significance　of　this　study　lies　in　its　implications　for　the　development　of　advanced　permanent　magnetic　materials　through　reduction-diffusion　technology.　©　2024　Elsevier　B.V.