Corrosion Behavior of Laser Direct Energy Deposited AISI 316L Stainless Steel in Hank’s Solution
Sharath Anishetty, Tapas Bera, Jyotsna Dutta Majumdar and Indranil Manna
This study concerns a detailed characterization of microstructure and evaluation of corrosion resistance (in Hank’s solution) of austenitic stainless steel (AISI 316L) substrate fabricated by laser direct energy deposition (LDED) using a 6 kW fibre coupled diode laser under the optimum process parameters of 600 W applied power, 5 mm/s scan speed and 50 g/min powder flow rate. LDED with optimum parameters leads to the refinement of microstructure with cellular morphology of predominantly austenitic grains. The corrosion test in Hank’s solution shows almost an order of magnitude lower corrosion rate than commercially available wrought AISI 316L. Similarly, immersion in simulated body fluid shows higher kinetics of calcium phosphate deposition on LDED AISI 316L than that on the same steel in wrought condition.
Keywords: Austenitic stainless steel, laser direct energy deposition, bioimplant, corrosion, bioactivity