The effects of the filler metal powder with different ratios of W, Mo, Ta and B on the TLP bonded region of superalloy GTD-111DS

The mixing ratio effect of the powder W, Mo, Ta and B insert metal powder on Transient Liquid Phase bonding phenomenon and on the mechanical properties were investigated. The N5, MN5 and MN6 insert metal powder was eliminated by isothermal solidification which was controlled by the diffusion of B into the base metal and the insert metal powder was created some polycrystal in bonded interlayer but The solids in the bonded interlayer grew epitaxially from the base metal near the bonded interlayer inward the insert metal during the isothermal solidification. The number of grain boundaries formed at the bonded interlayer corresponded with those of base metal. When the isothermal solidification was finished, the concentration of the boned interlayer was similar with base metal. The tensile strength of N5 insert metal powder was the highest in insert metal powder as 1,070 MPa. At the creep rupture, The fracture time of N5 insert metal powder was similar to base metal by 81 hours (stress 345 MPa, 870 degrees C) but elongation, reduction area was lower than base metal. At the mixing ratio of MN7 insert metal powders, the polycrystal in the bonded interlayer was formed when the isothermal solidification finished.