Gravity　and　centrifugal　investment　casting　processes　of　low-pressure　turbine　blades　with　high　Nb-TiAl　alloy　were　simulated　by　Procast　software.　Actual　blade　components　were　poured　by　vacuum　induction　suspended　furnace　with　Ar　protection.　The　experimental　verification　indicated　that　the　simulation　results　were　in　good　agreement　with　the　experimental　results.　Comparative　results　had　shown　that　the　surface　of　centrifugal　casting　blade　was　more　complete　than　that　of　gravity　casting　one.　In　gravity　casting　process,　molten　metal　filled　the　thinnest　trailing　edge　at　last,　resulting　in　the　generation　of　misrun　defects.　Furthermore,　the　shrinkage　porosity　and　crack　defects　of　gravity　casting　were　much　more　and　dispersive.　The　internal　and　external　quality　of　centrifugal　casting　was　much　better　than　that　of　gravity　casting.　Microstructures　from　edge　to　center　of　gravity　casting　blade　had　no　significant　change.　The　microstructure　for　centrifugal　casting　blade　is　finer　than　that　for　gravity　casting　blade,　however,　a　large　number　of　dentritic　y　segregation　appeared　in　the　blade　edge　of　centrifugal　casting,　which　resulted　from　the　fast　cooling　rate　of　centrifugal　casting　surface.　(C)　2015　Elsevier　Ltd.　All　rights　reserved.