The　competitive　growth　mechanism　of　columnar　grains　generated　from　rapid　solidification　in　plasma-sprayed　yttria-stabilized　zirconia　(YSZ)　splats　collected　on　stainless　steel　at　different　temperatures　was　studied.　The　microstructure　of　YSZ　splats　was　examined　quantitatively　by　scanning　electron　microscope　and　x-ray　diffraction.　The　crystalline　orientation　of　columnar　grains　was　investigated　by　electron　backscattered　diffraction.　It　was　found　that　the　competition　between　the　columnar　grains　was　governed　by　their　relative　growing　rate.　The　columnar　grains　with　growing　face　(001)　had　the　slowest　growing　rate,　while　those　with　growing　face　{011}　had　the　fastest　growing　rate.　The　degree　of　competition　between　the　columnar　grains　was　related　to　the　nucleation　rate　for　the　splat　at　different　substrate　temperatures　(Ts).　When　the　splat　was　at　Ts = 300 K　or　Ts = 373 K,　the　relatively　low　nucleation　rate　resulted　in　less　competition　between　the　columnar　grains;　thus,　no　preferential　orientation　was　observed.　In　contrast,　for　the　splat　at　Ts = 473 K,　the　higher　nucleation　rate　resulted　in　more　competition　between　the　columnar　grains,　increasing　the　proportion　of　grains　with　the　faster　growing　face　{011},　and　therefore,　the　columnar　grains　show　〈011〉　preferential　orientation.　©　2015,　ASM　International.