Metallurgical Investigation on the Effect of BZL Welding of LPTR Blase Shrouded Tips of Aero Engines

Abstract

BZL welding and assembly procedure could be an area of concern for failure of LPTR blades of acro engines that might have caused number of accidents of aircrafts. So the present investigation is aimed to understand the effect of number of times BZL welding performed on microstructure and properties of the LPTR blades shrouded tips.Hence four numbers of LPTR blades of R-29 aero engine with different number of times BZL welding carried out were investigated and the results were presented. The increase in grain size of the LPTR blade tip was observed with number of times BZL welding was carried out. Rounding of y' (gamma prime) phase is occurring with BZL weldings. The dissolution of y' (gamma prime) phase near interface between base metal and weld metal is observed. However, there is not much appreciable change in hardness of the blade tips with number of times BZL weldings performed were observed. Moreover all the BZL welded blade tips have compressive residual stress.