Effect of atomizing gas pressure on spray formed 7075 alloy

7075 Al alloy spray formed at various atomizing gas pressures is dealt in detail. Argon gas atomization of the molten alloy results in a spray deposit collected on a copper substrate. Three different atomizing pressures chosen for study are 0.7, 1.0 and 1.6 MPa, the other experimental parameters remaining the same. The variation in gas pressure has an impact on the yield and porosity distribution. Yield increases as gas pressure increases, whereas at 1.0 MPa pressure the deposit is found to be of more dense as compared to the other two pressures. Non destructive test, optical and scanning electron microscopy are used for the assessment of porosity distribution. Porosity due to solidification shrinkage is observed in the spray deposit at 0.7 and 1.0 MPa, however, spray deposit at 1.6 MPa exhibits both solidification and interstitial porosity. Hot extrusion at 380 degreesC increases the density to 99.5%. High strength and very good ductility after extrusion are exhibited in tensile test.