Abstract
This paper investigates a universal law of the relationship between the particle diameter and material density, to provide almost identical particle velocity distribution for two or more spray particles with different material density, by using onedimensional calculation. The spray materials selected in this investigation were Ti, Cu and WC-12Co. The universal law was constructed through the calculation of cold-sprayed particle velocities. Then, the validity of the universal law was verified by the calculations of particle velocity of warm spray and HVOF thermal spray. Special attention was paid to the particle velocity outside the thermal spray guns. The calculated results reveal that 1) when the particle diameter dp is selected for an arbitrary material density ρp against a set of reference diameter and material density based on the proposed universal law, the particle velocity outside the thermal spray gun becomes almost identical to the velocity of the reference particle within the accuracy of around ±6% in the range of 1,700 < dpρp0.72 < 30,000 μm(kg/m3)0.72, 2) the proposed universal law can be applicable to thecold spray, warm spray and HVOF thermal spray.
