A Ti-5.4Al-6.4Zr-6.2Sn-0.4Mo-1.6W-0.4Nb-3.2Ta-0.5Si alloy is designed following cluster formula approach that achieves a strength level of 1 GPa at 600℃in the as-cast state,superior to any existing high-temperature T...A Ti-5.4Al-6.4Zr-6.2Sn-0.4Mo-1.6W-0.4Nb-3.2Ta-0.5Si alloy is designed following cluster formula approach that achieves a strength level of 1 GPa at 600℃in the as-cast state,superior to any existing high-temperature Ti alloys.Its composition is formulated by 17 basic units,α-{[Al-Ti12](AlTi2)}12+β-{[Al-Ti_(12)Zr_(2)](Mo_(0.125)Nb_(0.125)Ta_(0.5)W_(0.25)Sn_(1.5)Si_(0.5))}_(5),each unit covering a nearest-neighbor cluster plus a few next-neighbor glue atoms.This design is on the basis of the composition formula of Ti65 alloy,with an enhancedβstability via more Zr,Mo,Nb,Ta,W,Sn,and Si co-alloying.Upon copper-mold pour casting,this alloy shows a good microstructure stability.In tensile testing below at 650℃,itsαplates thickness is nearly at the same level of 0.2μm,which is much smaller than 0.7-0.8μm of Ti65 at the same condition.The changes in volume fraction ofβphase are increased by 86%,much less than by 105%in Ti65.Its room-temperature strength reaches the ultra-high-strength level,with an ultimate tensile strength of 1328 MPa and a yield strength of 1117 MPa,with a moderate elongation of 3.8%.At 600℃,its ultimate tensile strength of 1017 MPa and yield strength of 936 MPa are superior to those of any existing high-temperature Ti alloys,with an elongation of 7.2%.At 650℃,its ultimate tensile strength of 848 MPa still maintains a high level.展开更多
基金supported by the Natural Science Foundation of Shenyang,China(Grant No.22315605)the“Rejuvenating Liaoning Talents Plan”Project of Liaoning Province(Grant No.XLYC2203121)the Outstanding Youth Science and Technology Talent Project of Dalian(Grant No.2023RY040).
文摘A Ti-5.4Al-6.4Zr-6.2Sn-0.4Mo-1.6W-0.4Nb-3.2Ta-0.5Si alloy is designed following cluster formula approach that achieves a strength level of 1 GPa at 600℃in the as-cast state,superior to any existing high-temperature Ti alloys.Its composition is formulated by 17 basic units,α-{[Al-Ti12](AlTi2)}12+β-{[Al-Ti_(12)Zr_(2)](Mo_(0.125)Nb_(0.125)Ta_(0.5)W_(0.25)Sn_(1.5)Si_(0.5))}_(5),each unit covering a nearest-neighbor cluster plus a few next-neighbor glue atoms.This design is on the basis of the composition formula of Ti65 alloy,with an enhancedβstability via more Zr,Mo,Nb,Ta,W,Sn,and Si co-alloying.Upon copper-mold pour casting,this alloy shows a good microstructure stability.In tensile testing below at 650℃,itsαplates thickness is nearly at the same level of 0.2μm,which is much smaller than 0.7-0.8μm of Ti65 at the same condition.The changes in volume fraction ofβphase are increased by 86%,much less than by 105%in Ti65.Its room-temperature strength reaches the ultra-high-strength level,with an ultimate tensile strength of 1328 MPa and a yield strength of 1117 MPa,with a moderate elongation of 3.8%.At 600℃,its ultimate tensile strength of 1017 MPa and yield strength of 936 MPa are superior to those of any existing high-temperature Ti alloys,with an elongation of 7.2%.At 650℃,its ultimate tensile strength of 848 MPa still maintains a high level.
