High niobium β-γ TiAl alloy(HNBG) was diffusion bonded using spark plasma sintering with pure Ti as interlayer. The joint microstructural evolution, growth kinetics and mechanical properties were investigated. The j...High niobium β-γ TiAl alloy(HNBG) was diffusion bonded using spark plasma sintering with pure Ti as interlayer. The joint microstructural evolution, growth kinetics and mechanical properties were investigated. The joint included three diffusion zones. The β/B2 phase formed in the Zone Ⅰ, α_(2)phase in the Zone Ⅱ, and β-Ti and α-Ti phases in the Zone Ⅲ. The thickness of β/B2 phase, the average grain size of α_(2)phase and the amount of β-Ti phase increased with the increase of bonding temperature or bonding time. The growth activation energies of β/B2 and α_(2)phases were 582 and 253 kJ/mol, respectively. The joint acquired at 1000 °C, 10 min and 10 MPa showed the maximum shear strength of 308 MPa. Fracture mainly occurred along the interfaces between Zone Ⅰ and HNBG alloy, and between Zone I and Zone Ⅱ. Fracture mechanism of the joint was characterized by brittleness rupture along the phase boundary.展开更多
Reaction behaviors occurring in Ti/Al foil metallurgy were systematically investigated.Particular emphasis was focused on the reaction between solid Al and Ti as well as subsequent reaction between TiAland Ti layer.In...Reaction behaviors occurring in Ti/Al foil metallurgy were systematically investigated.Particular emphasis was focused on the reaction between solid Al and Ti as well as subsequent reaction between TiAland Ti layer.In the solid reaction between Al and Ti,the presence of residual Al is mainly caused by inhomogeneous growth of TiAllayer and micro-voids existing at the interface.However,through reaction between molten Al and Ti,TiAl/Ti multilayer can be achieved with complete consumption of Al.During subsequent high-temperature heat treatment,TiAl/Ti multilayer will eventually turn into TiAl/TiAl multilayer accompanying with simultaneous formation and successive disappearance of intermediate phases,such as TiAland TiAl.Moreover,it is found that the growth direction of TiAl layer changes as a function of annealing time between different couples in multi-intermetallics system.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 51871012, 52071021)Beijing Natural Science Foundation (No. 2162024)+1 种基金Fundamental Research Funds for the Central Universities, China (No. FRF-GF-20-20B)the National Key Basic Research Program of China (No. 2011CB605502)。
文摘High niobium β-γ TiAl alloy(HNBG) was diffusion bonded using spark plasma sintering with pure Ti as interlayer. The joint microstructural evolution, growth kinetics and mechanical properties were investigated. The joint included three diffusion zones. The β/B2 phase formed in the Zone Ⅰ, α_(2)phase in the Zone Ⅱ, and β-Ti and α-Ti phases in the Zone Ⅲ. The thickness of β/B2 phase, the average grain size of α_(2)phase and the amount of β-Ti phase increased with the increase of bonding temperature or bonding time. The growth activation energies of β/B2 and α_(2)phases were 582 and 253 kJ/mol, respectively. The joint acquired at 1000 °C, 10 min and 10 MPa showed the maximum shear strength of 308 MPa. Fracture mainly occurred along the interfaces between Zone Ⅰ and HNBG alloy, and between Zone I and Zone Ⅱ. Fracture mechanism of the joint was characterized by brittleness rupture along the phase boundary.
基金financially supported by the National Basic Research Program of China(No.2011CB605501)the National Natural Science Foundation of China(Nos.U1204508 and 51171015)the Project of State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing(No.2012Z-11)
文摘Reaction behaviors occurring in Ti/Al foil metallurgy were systematically investigated.Particular emphasis was focused on the reaction between solid Al and Ti as well as subsequent reaction between TiAland Ti layer.In the solid reaction between Al and Ti,the presence of residual Al is mainly caused by inhomogeneous growth of TiAllayer and micro-voids existing at the interface.However,through reaction between molten Al and Ti,TiAl/Ti multilayer can be achieved with complete consumption of Al.During subsequent high-temperature heat treatment,TiAl/Ti multilayer will eventually turn into TiAl/TiAl multilayer accompanying with simultaneous formation and successive disappearance of intermediate phases,such as TiAland TiAl.Moreover,it is found that the growth direction of TiAl layer changes as a function of annealing time between different couples in multi-intermetallics system.
