Liquidus projection usually refers to a two-dimensional projection of ternary liquidus univariant lines at constant pressure. The algorithms used in Pandat for the calculation of liquidus projection with isothermal li...Liquidus projection usually refers to a two-dimensional projection of ternary liquidus univariant lines at constant pressure. The algorithms used in Pandat for the calculation of liquidus projection with isothermal lines and invariant reaction equations in a ternary system are presented. These algorithms have been extended to multicomponent liquidus projections and have also been implemented in Pandat. Some examples on ternary and quaternary liquidus projections are presented.展开更多
Abstract The as-cast microstructures and solidification paths of the Nb-Si-Ti ternary alloys in the NbsSi3-TisSi3 region were investigated. Since there exist some isomor- phous compounds in the NbsSi3-TisSi3 region, s...Abstract The as-cast microstructures and solidification paths of the Nb-Si-Ti ternary alloys in the NbsSi3-TisSi3 region were investigated. Since there exist some isomor- phous compounds in the NbsSi3-TisSi3 region, such as aNbsSi3 with B3Cr5 prototype, 13NbsSi3 with Si3W5 pro- totype, 7NbsSi3 with MnsSi3 prototype, and TisSi3 with MnsSi3 prototype, the primary solidification areas of these compounds were not typically indentified in previous experiments. In the present paper, the microstructure observation, the phase identification, and the composition measurement were performed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and electron probe microanalysis (EPMA), respectively. No ternary compound is found. There exist three primary solidification areas, 13Nbs_x(Ti)xSi3, ~Nbs_x(Ti)xSi3, and Tis-x(Nb)xSi3 in the NbsSi3-TisSi3 region. Together with the literaturereported experimental data and optimization results, the liquidus projection of the whole Nb-Si-Ti ternary system is constructed, and totally ten primary solidification areas-- diamond-Si, Nb1-x(Ti)xSi2, Ti1-x(Nb)xSi2, Ti1-x(Nb)xSi, Ti5-x(Nb)xSi4, βNb5-x(Ti)xSi3,αNb5-x(Ti)xSi3, Ti5-x (Nb)xSi3, (Nb,Ti)3Si, and BCC--and nine transitional invariant reactions-L + Nb1-x(Ti)xSi2 → Ti1-x(Nb)x Si2 + Si, L + Nb1-x(Ti)xSi2 → Ti1-x(Nb)xSi2 + Ti5- (Nb)xSi4, L + Ti5-x(Nb)xSi4 → Ti1-x(Nb)xSi2 + Ti1-x (Nb)xSi, L + 13Nb5-x(Ti)5Si3→ Nb1-x(Ti)xSi2 + Ti5-x (Nb)xSi4, L + βNb5-x(Ti)xSi3→b5-x(Ti)xSi3 +Ti5-x (Nb)xSi4, L + αNb5-x(Ti)αSi3 → Ti5-x(Nb)xSi3 + Ti5-x(Nb)x Si4, L + αNb5-x(Ti)xSi3 →βNb5-x(Ti)xSi3 + Ti5-x(Nb)xSi3, L + βNb5-xTb-xSi3 → Ti5-x(Nb)xSi3 + (Nb,Ti)3Si, and L + (Nb,Ti)3Si → Ti5-x(Nb)xSi3 + BCC are confirmed.展开更多
文摘Liquidus projection usually refers to a two-dimensional projection of ternary liquidus univariant lines at constant pressure. The algorithms used in Pandat for the calculation of liquidus projection with isothermal lines and invariant reaction equations in a ternary system are presented. These algorithms have been extended to multicomponent liquidus projections and have also been implemented in Pandat. Some examples on ternary and quaternary liquidus projections are presented.
基金supported by the National Natural Science Foundation of China (No. 51271027)the National High Technology Research and Development Program of China (No. 2013AA031601)
文摘Abstract The as-cast microstructures and solidification paths of the Nb-Si-Ti ternary alloys in the NbsSi3-TisSi3 region were investigated. Since there exist some isomor- phous compounds in the NbsSi3-TisSi3 region, such as aNbsSi3 with B3Cr5 prototype, 13NbsSi3 with Si3W5 pro- totype, 7NbsSi3 with MnsSi3 prototype, and TisSi3 with MnsSi3 prototype, the primary solidification areas of these compounds were not typically indentified in previous experiments. In the present paper, the microstructure observation, the phase identification, and the composition measurement were performed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and electron probe microanalysis (EPMA), respectively. No ternary compound is found. There exist three primary solidification areas, 13Nbs_x(Ti)xSi3, ~Nbs_x(Ti)xSi3, and Tis-x(Nb)xSi3 in the NbsSi3-TisSi3 region. Together with the literaturereported experimental data and optimization results, the liquidus projection of the whole Nb-Si-Ti ternary system is constructed, and totally ten primary solidification areas-- diamond-Si, Nb1-x(Ti)xSi2, Ti1-x(Nb)xSi2, Ti1-x(Nb)xSi, Ti5-x(Nb)xSi4, βNb5-x(Ti)xSi3,αNb5-x(Ti)xSi3, Ti5-x (Nb)xSi3, (Nb,Ti)3Si, and BCC--and nine transitional invariant reactions-L + Nb1-x(Ti)xSi2 → Ti1-x(Nb)x Si2 + Si, L + Nb1-x(Ti)xSi2 → Ti1-x(Nb)xSi2 + Ti5- (Nb)xSi4, L + Ti5-x(Nb)xSi4 → Ti1-x(Nb)xSi2 + Ti1-x (Nb)xSi, L + 13Nb5-x(Ti)5Si3→ Nb1-x(Ti)xSi2 + Ti5-x (Nb)xSi4, L + βNb5-x(Ti)xSi3→b5-x(Ti)xSi3 +Ti5-x (Nb)xSi4, L + αNb5-x(Ti)αSi3 → Ti5-x(Nb)xSi3 + Ti5-x(Nb)x Si4, L + αNb5-x(Ti)xSi3 →βNb5-x(Ti)xSi3 + Ti5-x(Nb)xSi3, L + βNb5-xTb-xSi3 → Ti5-x(Nb)xSi3 + (Nb,Ti)3Si, and L + (Nb,Ti)3Si → Ti5-x(Nb)xSi3 + BCC are confirmed.