Microstructure and mechanical properties of titanium deposits by warm spray were investigated in the as-sprayed and heat-treated conditions with an aim to find the optimal for the spray process and heat treatment. Coatings were deposited with different nitrogen flow rates in a range from 0.5 to 1.5 m~3/min. It was found that spray parameters, which affect the temperature and velocity of in-flight particles, have significant effects on the properties of the fabricated coatings. Recently, the combustion pressure of warm spray has been raised from 1 to 4 MPa resulted in increase in particle velocity above 1,000 m/s. This modification had significant beneficial effects in terms of improving density and controlling the oxygen level in Ti coatings. Mini specimens with total length of about 9 mm were used to perform tensile tests for the Ti deposits. The optimal set of mechanical properties was found for specimens formed at a middle range of nitrogen flow rate (0.75 m~3/min). Additionally, several heat treatments were performed in order to enhance the mechanical properties of as-sprayed coatings. It was found that the post-spray heat treatment improve the bonding between deposited particles, which significantly enhanced the strength and plasticity of the Ti coatings.
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