Influence of Etchants on Phase Morphology of Casting Ni-Based Superalloy
K4169 is the Nickel-base superalloy that is the most widely used in the turbine components. The article selects three kinds of etching solution to corrode, in order to achieve the purpose that studies on its morphology. Etchant1 is the mixed solution of 15mlHCl, 10mlAcetic acid, 5mlHNO3and 2drop glycerin. Etchant2 is the mixed solution of 3ml glycerin, 3mlHCl, 1ml HNO3. Etchant 3 is the mixed solution of 20mlHNO3, 60mlHCl. The results showed that we can mainly observe strengthened phase γ'' (Ni3(Ti, Al)) and matrix γ (Fe-Ni-Cr) phase with etchant1 to corrode. Using the etchant2 to corrode, we can clearly see its dendrite structure. Using the etchant3 to corrode, we can obverse its grain boundary that includes white inter-metallic compounds. We also respectively discussed the K4169 morphology when magnifications are 200times and 500times.