The influence of microstructure,heat treatment and alloying addition on mechanical and fracture properties of Ti3Al-basedintermetallic at room and elevated temperatures was studied.Ti3Al?11Nb?1Mo(mole fraction,%)alloy...The influence of microstructure,heat treatment and alloying addition on mechanical and fracture properties of Ti3Al-basedintermetallic at room and elevated temperatures was studied.Ti3Al?11Nb?1Mo(mole fraction,%)alloy was consolidated viapowder metallurgy processing by mechanical alloying(MA)and hot pressing(HP).MA powders were characterized using XRD andSEM-EDS.Optimum MA duration was25h and HP conditions of1350°C,2h,35MPa.After HP,solution treatment at1050°C for1h and water quenchingα2+βWidmanst?tten microstructure is present,while subsequent aging at800°C during24h induces smallcontent of O-phase.High fraction ofβ-phase is a direct consequence of Mo.Compression tests were performed from roomtemperature to750°C in vacuum.The yield strength of compacts increases with temperature up to250°C(pyramidal slip systemsactivation),after which it decreases.Ductility increases throughout the whole temperature range.The presence of O phasecontributed to ductility increase in aged alloys,while negligibly lowering yield strength.Registered drop in the yield strength of agedalloys compared with non-aged ones was mostly influenced by precipitation ofα″2particles.Mixed fracture modes are operative atall temperatures.展开更多
基金financially supported by the Ministry of Education,Science and Technological Development of the Republic of Serbia through the Project(No.172005).
文摘The influence of microstructure,heat treatment and alloying addition on mechanical and fracture properties of Ti3Al-basedintermetallic at room and elevated temperatures was studied.Ti3Al?11Nb?1Mo(mole fraction,%)alloy was consolidated viapowder metallurgy processing by mechanical alloying(MA)and hot pressing(HP).MA powders were characterized using XRD andSEM-EDS.Optimum MA duration was25h and HP conditions of1350°C,2h,35MPa.After HP,solution treatment at1050°C for1h and water quenchingα2+βWidmanst?tten microstructure is present,while subsequent aging at800°C during24h induces smallcontent of O-phase.High fraction ofβ-phase is a direct consequence of Mo.Compression tests were performed from roomtemperature to750°C in vacuum.The yield strength of compacts increases with temperature up to250°C(pyramidal slip systemsactivation),after which it decreases.Ductility increases throughout the whole temperature range.The presence of O phasecontributed to ductility increase in aged alloys,while negligibly lowering yield strength.Registered drop in the yield strength of agedalloys compared with non-aged ones was mostly influenced by precipitation ofα″2particles.Mixed fracture modes are operative atall temperatures.
