EFFECT OF ELECTRON BEAM RE-MELTING ON SURFACE MOTPHOLOGY AND PROPERTIES OF SILICIDE COATING

The silicide coating was prepared by fused slurry method on Nb521 alloy,the silicide coating was re-melted by high frequency electron beam,the morphology of specimen was analyzed by SEM.It is found that after electron beam re-melt process,the surface ceramic grain granularity and surface roughness decrease,the sintering effect between ceramic grains increased,the obvious boundary was found between primary region and region re-melted,it prove that the energy distributing is well-proportioned.The silicide coating’ sintering effect increased after EB re-melting process,and the coating became dense,the surface roughness of coating decrease,the high-temperature oxidation resistance and shock testing validate capability improved.