The transmission electron microscopy was employed to investigate the microstructure of infrared brazed highstrength Ti alloy using the Ti-15Cu-15Ni filler metal. Coarse primary Ti2Ni and transformed β-Ti are observed...The transmission electron microscopy was employed to investigate the microstructure of infrared brazed highstrength Ti alloy using the Ti-15Cu-15Ni filler metal. Coarse primary Ti2Ni and transformed β-Ti are observed in the 300 s brazed specimen. Blocky Ti2Ni and eutectoid Ti2Cu intermetallics are disappeared from the joint with increasing the brazing time to 1800 s. Both acicular α-Ti and retained β-Ti dominate the entire brazed joint.展开更多
Microstructural evolution of infrared vacuum brazed CP-Ti using two Ti-based braze alloys,Ti-15Cu-15Ni and Ti-15Cu-25Ni,has been investigated.The infrared brazed joint consisted of eutectic Ti 2 Cu/Ti 2 Ni intermetall...Microstructural evolution of infrared vacuum brazed CP-Ti using two Ti-based braze alloys,Ti-15Cu-15Ni and Ti-15Cu-25Ni,has been investigated.The infrared brazed joint consisted of eutectic Ti 2 Cu/Ti 2 Ni intermetallic compounds and Ti-rich matrix.The eutectic Ti 2 Cu/Ti 2 Ni intermetallic compounds disappeared from the joint after being annealed at 900 C for 1 h.In contrast,the depletion rate of both Cu and Ni from the braze alloy into CP-Ti substrate at 750 C annealing was greatly decreased as compared with that annealed at 900 C.Blocky Ti 2 Cu/Ti 2 Ni phases were observed even if the specimen was annealed at 750 C for 15 h.Because the Ni content of the Ti-15Cu-25Ni braze alloy is much higher than that of the Ti-15Cu-15Ni alloy,the amount of eutectic Ti 2 Cu/Ti 2 Ni phases in Ti-15Cu-25Ni brazed joint is more than that in Ti-15Ci-15Ni brazed joint.However,similar microstructural evolution can be obtained from the infrared brazed joint annealed at various temperatures and/or time for both filler metals.展开更多
基金financial support of this research by the National Science Council(NSC),Taiwan,China,under the grant number 98-2221-E-002-052
文摘The transmission electron microscopy was employed to investigate the microstructure of infrared brazed highstrength Ti alloy using the Ti-15Cu-15Ni filler metal. Coarse primary Ti2Ni and transformed β-Ti are observed in the 300 s brazed specimen. Blocky Ti2Ni and eutectoid Ti2Cu intermetallics are disappeared from the joint with increasing the brazing time to 1800 s. Both acicular α-Ti and retained β-Ti dominate the entire brazed joint.
基金support of this research by the National Science Council(NSC),Taiwan,China (Grant No.NSC 99-2221-E-002-051)
文摘Microstructural evolution of infrared vacuum brazed CP-Ti using two Ti-based braze alloys,Ti-15Cu-15Ni and Ti-15Cu-25Ni,has been investigated.The infrared brazed joint consisted of eutectic Ti 2 Cu/Ti 2 Ni intermetallic compounds and Ti-rich matrix.The eutectic Ti 2 Cu/Ti 2 Ni intermetallic compounds disappeared from the joint after being annealed at 900 C for 1 h.In contrast,the depletion rate of both Cu and Ni from the braze alloy into CP-Ti substrate at 750 C annealing was greatly decreased as compared with that annealed at 900 C.Blocky Ti 2 Cu/Ti 2 Ni phases were observed even if the specimen was annealed at 750 C for 15 h.Because the Ni content of the Ti-15Cu-25Ni braze alloy is much higher than that of the Ti-15Cu-15Ni alloy,the amount of eutectic Ti 2 Cu/Ti 2 Ni phases in Ti-15Cu-25Ni brazed joint is more than that in Ti-15Ci-15Ni brazed joint.However,similar microstructural evolution can be obtained from the infrared brazed joint annealed at various temperatures and/or time for both filler metals.
