Kinetics of isothermal solidification during transient liquid phase bonding of Inconel 718 superalloy by differential scanning calorimetry

Abstract

In the transient liquid phase bonding of Inconel 718 alloy, the time for isothermal solidification is measured by using the cyclic differential scanning calorimetry method. The enthalpy of solidification of the remnant liquid is used in the current investigation to determine the isothermal solidification rate and time. The differential scanning calorimetry results reveal a reduction in interlayer width during the heating and melting stage of transient liquid phase bonding due to the rapid interdiffusion of elements. The result also reveals that the isothermal solidification time for a eutectic-free joint depends upon the actual width of the interlayer material. The actual width of the interlayer material prior to isothermal solidification is found to be less than the initial width of the interlayer material due to rapid diffusional solidification. The measured isothermal solidification time and rate for transient liquid phase bonding of the Inconel 718 joint are in good agreement with the experimental and theoretical results.