PROCESSING,MICROSTRUCTURE AND MECHANICAL PROPERTIES OF LARGE DIRECTIONALLY SOLIDIFIED CASTINGS FOR INDUSTRIAL GAS TURBINE APPLICATIONS

Contamination of low melting point metal and distortion and fracture of ceramic shell during directional solidification assisted by liquid metal cooling(LMC) were discussed.Large DS castings with 430 mm in length were produced by optimizing the processing parameters.The microstructure,heat treatment response and typical creep rupture properties of the large casting were analyzed.Results of the preliminary casting trials of large blades were also reported.