Characterization of corrosion behaviour of laser beam formed titanium alloy

The application of Titanium and its alloys are found in various industries such as Aerospace, Human implant, Automotive, Chemical processing, Geothermal, and Armoury etc. The unique properties of Titanium have made it immune to all forms of environmental attacks such as the urban pollution, marine and industrial. However, it is believed that all manufacturing processes often influences the materials and mechanical properties of the processed material. This paper reports on the corrosion behaviour of Laser Beam Formed Titanium Alloy. Titanium sheets were laser formed using three constant parameters (laser power of 0.8 kW, the beam diameter of 12 mm and scan speed of 0.03 m/min) and varied parameter which is the number of scans - 3, 5 and 7. The corrosion behaviour was after that investigated in a 3.5% NaCl solution using the Potentiodynamic Polarization technique. The Potentiodynamic polarization curves were measured at a scan rate of 2 mV/s starting from 1000.0 mV concerning OCP to 1100 mV. The result revealed that the parent material had the most significant resistance to corrosion and the lowest corrosion rate per year. While for the Laser formed Titanium sheets, it was observed that as the number of scans increases the resistance to pitting was increased. However, the Titanium sheets samples formed at seven and five laser scans developed microcracks on the surface of the samples even though the resistance to corrosion is improved with the two sets of samples. These defects render the laser formed titanium sheets undesirable for intended applications.