Numerical Simulation of Low Porosity Al-Based Quasicrystalline Coatings Deposited by Warm Spray
摘要
Al-based quasicrystalline (QC) coatings with low porosity were fabricated by warm spraying using numerical simulation and experimental approaches. A gas-solid coupled computational fluid dynamics (CFD) model was established to simulate the warm spraying process.This study examined the influence of reactant mass flow rate (F), coolant mass flow rate (C), oxygen/fuel (O/F) ratio (R), particle mass flow rate (Q), spray distance (L), particle shape, particle injection angle, and particle injection velocity on the gas phase characteristics and particle flight dynamics. The optimum spraying parameters (OSP) are as follows: 0.010269 kg·s−1 for F, 0.004857 kg·s−1 for C, 2.6 for the R, 0.0005 kg·s−1 for critical Q, 140 mm for L, 10-25 µm for particle size range, spherical for particle shape, 0° for particle injection angle, and 10 m/s for particle injection velocity. Moreover, response surface methodology (RSM) was used to examine the effects of the spray process parameters on particles temperature/velocity. For particle temperature, F exerted the greatest effect, followed by C, L, R, and Q in descending order of significance. For particle velocity, F dominated, L, Q, C, and R showed progressively decreasing influence. Afterward, Al-based QC coating with low porosity (2.08%) was produced using the OSP by warm spraying experiments.