Laser beam welding was used to join a near-β titanium alloy(Ti-3Al-6Mo-2Fe-2Zr),followed by aging treatments.The relations among aging temperature,microstructure,and tensile properties of joints were revealed.For as-...Laser beam welding was used to join a near-β titanium alloy(Ti-3Al-6Mo-2Fe-2Zr),followed by aging treatments.The relations among aging temperature,microstructure,and tensile properties of joints were revealed.For as-welded joints,the fusion zone features primarily single β phase.It is attributed to the high Mo equivalency of this alloy and the fast cooling rate in laser beam welding.After aging treatments,many α precipitates form in the fusion zone and heat affected zone.The rising aging temperature coarsens α precipitates and reduces the volume fraction of α precipitates.Compared with the as-welded joints,the aging treated joints'tensile strength and elongation are improved.The increasing aging temperature weakens the strengthening effect because of the decreasing volume fraction of α precipitates.After the aging treatment at 500℃ for 8 h,the joints obtain the optimal match between strength and plasticity.The fracture mode of joints changes from quasi-cleavage fracture in as-welded condition to microvoid coalescence fracture after heat treatments.展开更多
基金National Natural Science Foundation of China(51804097)Fundamental Research Funds for the Central Universities of China(B220202026)Changzhou Sci&Tech Program(CJ20220074)。
文摘Laser beam welding was used to join a near-β titanium alloy(Ti-3Al-6Mo-2Fe-2Zr),followed by aging treatments.The relations among aging temperature,microstructure,and tensile properties of joints were revealed.For as-welded joints,the fusion zone features primarily single β phase.It is attributed to the high Mo equivalency of this alloy and the fast cooling rate in laser beam welding.After aging treatments,many α precipitates form in the fusion zone and heat affected zone.The rising aging temperature coarsens α precipitates and reduces the volume fraction of α precipitates.Compared with the as-welded joints,the aging treated joints'tensile strength and elongation are improved.The increasing aging temperature weakens the strengthening effect because of the decreasing volume fraction of α precipitates.After the aging treatment at 500℃ for 8 h,the joints obtain the optimal match between strength and plasticity.The fracture mode of joints changes from quasi-cleavage fracture in as-welded condition to microvoid coalescence fracture after heat treatments.
