Research On The Surface Strengthening Of7075Aluminum Alloy By Electro-spark Deposition

Electro-spark deposition (ESD) surface strengthening technology is through the highenergy density of power to strengthen the base material, the electrode material meltinfiltration into the surface of substrate, forming metallurgical strengthening layer, so as tochange the physical properties, chemical properties of substrate material. In recent years, theelectric spark surface strengthening technology has been widely used in the field of materialsurface engineering, used for strengthening and repair of metal material surface. This articleselects the pure titanium TA2as electrode,7075aluminum alloy as substrate material, undernitrogen atmosphere protection for ESD surface strengthening, discussed the strengtheningbehavior of coating.In this paper, in-depth study of the reinforcement layer thickness and the factorsaffecting the quality. Get the varying pattern of einforcement layer thickness changing withthe deposition process(output voltage, deposition time, discharge capacity and dischargefrequency), also obtained the best process parameters. Explores the forming mechanism of thedeposit, the characteristics of sedimentary point surface morphology, and the mass transferregularity of materials, analyzed the sedimentary composition, element distribution,microstructure and interface behavior, test the hardness distribution and sedimentary depositsof corrosion resistance. The results showed that the substrate material and electrode materialbetter metallurgical combination, coatings are uniform, dense and continuous, averagethickness is70microns; Strengthening layer of hardness is295HV,2times of the substratehardness; Corrosion resistance is also a certain degree of improvement.