Effect of Plasma Nitriding on Structure and Properties of Titanium Grade 2 Produced by Direct Metal Laser Sintering

This article presents the effect of an Indirect Plasma Nitriding process on the microstructure and properties of Titanium Grade- 2 samples manufactured by Direct Metal Laser Sintering Method (DMLS). It was determined, based on morphological analysis that the physical and chemical phenomena occurring at the surface during nitriding has a decisive effect on surface roughening. Phase and stress analysis shown the nitrided layer produced in a pure nitrogen at 760 degrees C and containing TiN + TiN0.30 + Ti2N is under compressive stress and its characteristic of a high hardness and Young Modulus as compare to Grade 2 titanium samples produced only by DMLS technique (without nitriding). Static tensile stress carried out at room temperature show that the nitrided samples containing TiN + TiN0.30 + Ti2N have much lower yield (YS0.2) and tensile strength (UTS) compared to the not nitrided samples. Tests carried out in Ringer's solution, using impedance and potentiodynamic methods at temperatures elevated to 36.6 +/- 0.3 degrees C to simulate human-'s' body temperature, show that nitriding increased corrosion resistance of the alloy.