The Contribution Of Eutectic Y-Y' Liquid Film To The Tmaz Microfissuring In Inertia Friction Welded Pm Rrloqo Superalloy

Abstract: The microstructure of the base alloy and thermomechanical affected zone (TMAZ) of

inertia friction welded powder metallurgy (PM) RR1000 were examined by the use of stan'dard

metallograpllic tecl~niques involving optical. analytical scanning and msrnission elmtron

inicmsmpes equipped with enew dispersive spectrometer nnd an electron probe micro analyscr.

It was discovered that liquation of grain boundary phases present in the pre-weld alloy resulted in

the formation of eutectic type y-y' soIute rich liquid film predominant in the TMAZ regions whiel~

contributed significantly to microfissuring during welding. It was found that apart from the effect

of rapid precipitation of y' particles on the TMAZ cracking as has been widely reported,

constitutional liquation o f y' particles was a notable part of tiquation process rvhicl~p rornokd the

susceptibility oFTMAZ to microcracking.

Keywords: Nickel alloys; inertia frictioo ~rjeldihg;C o~~Iif~tli~/riq~uaait ion; SupraI/oys; TMZ

micrajssuring

Read Download