Comparison of Titanium Cold Spray Coatings

The deposition characteristics of titanium coatings deposited by the cold spray process using two different cold spray systems were evaluated. Commercially pure titanium feed stock powders were utilized to generate titanium coatings that were deposited on both aluminum and titanium substrates. The microstructure of the feedstock powders and deposited coatings were examined using optical and scanning electron microscopy. The characteristics of the cold spray titanium coatings were evaluated using density, hardness and bond strength measurements. As in the case of many cold spray deposited coatings, it was found that the characteristics of the feedstock powder has a significant influence on the characteristics of the resultant cold spray coating. The cold spray titanium coatings had greater than 10,000 psi bond strength to both aluminum and titanium substrates and exhibited 99% of the theoretical density of pure titanium. Due to work hardening via plastic deformation induced by cold spraying, the titanium coatings have twice the hardness of wrought titanium.