A rapid forming method and simulation on controllable-porosity coating

A new method was introduced to fabricate porous coating and control its porosity by changing spray parameters. Two models were constructed to simulate the deformation of droplet and the deposition process of splats on substrate. Considering the gap-pore, step-pore and shield-pore in the presented models, the influence of spray angle on the porosity of coating was mainly investigated. The simulation and experimental results show that the presented method is suitable for fabricating controllable-porosity coating. The porosity of coating can reach 49%. When the spray angle is lower than 30°, the porosity of coating rapidly increases because of shielding effect. Moreover, power size and impact velocity also influence the porosity. Besides, a new forming method of graded porous coating was simulated by continuously changing the spray angle. Supported by the National Natural Science Foundation of China (Grant Nos. 50474053, 50475134)