High-temperature tensile fracture behavior of directionally solidified Ni, Cr, Al-TaC eutectic superalloy

The high-temperature tensile fracture behavior of the Ni, Cr, Al-TaC eutectic superalloy directionally solidified under high temperature gradient is investigated. The high-temperature tensile fracture of this in situ composite has ductile character with lots of ductile nests whose diameters decrease with the increasing solidification rates. The maximum σ_b, and δ are respectively 668.5 MPa and 19.6%. There is a TaC whisker in the center of each nest, and the deformation of γ′ and TaC is uneven. The high-temperature tensile behavior cannot be explained by the rule of mixtures but is decided by the formation of the plastic deformation band. The crack extension model is given.