Surface Modification Of DZ22 Nickel-base Superalloy By High Current Pulsed Electron Beam

In this paper,a high current pulsed electron beam(HCPEB)device was used to bombard DZ22 nickel-based superalloy at different times with the same acceleration voltage.The experiment used to test the surface microstructure and macroscopic properties of DZ22 alloy before and after bombardment.The experimental results show that after the bombardment,the surface of the alloy forms a volcanic pit shape,and multiple bombardments also reduce the casting defects on the surface of the alloy.The number of different bombardments affects the number and position of the gamma prime phase of the alloy surface;after bombardment,a remelted layer and heat affected zone are formed on the alloy surface,and the thickness of the remelted layer and heat affected zone increases with the number of bombardments.increase.Simulation results of the temperature field when the simulation software bombarded the alloy surface showed that the surface temperature of the alloy was rapidly increased(about 2.8×109°C/S)and cooled(about9.2×107°C/S)during bombardment,and the surface layer reached the surface during bombardment.The maximum temperature(1629 °C)exceeds the melting point of the alloy.The structure of M23C6 high-melting carbide appears on the surface of the alloy after bombardment.The number of bombardment times will also affect the number and morphology of the high-melting carbides.The bombardment will also cause the grain growth direction of the alloy surface to be uniform and grain refinement.The surface stress state changes.The results of nanoindentation experiments show that with the increase of the number of bombardment,the surface elastic modulus,hardness and resistance to plastic deformation of the alloy are reduced.Cross-section microhardness test results show that different bombardment times have different effects on the microhardness of the alloy section.The high temperature oxidation test and hot corrosion test were conducted on the alloy surface before and after bombardment.The experimental results show that with the increase of the number of bombardment,the high temperature oxidation resistance and heat corrosion resistance of the alloy surface are enhanced.