Views: 0 Author: Site Editor Publish Time: 2025-09-04 Origin: Site
Thermal spraying is a widely used technology for surface repair and protection, which can effectively enhance the wear resistance, corrosion resistance and high-temperature resistance of materials. When conducting thermal spraying, choosing the appropriate thermal spraying parameters is of vital importance, as it directly affects the quality and performance of the coating.
Firstly, thermal spraying parameters include spraying temperature, spraying speed, gas flow rate, powder particle size, etc. The selection of these parameters needs to be adjusted according to specific application requirements and material properties. For instance, excessively high spraying temperatures may cause deformation of the substrate, while excessively low temperatures may result in insufficient adhesion of the coating. Therefore, when choosing the parameters for thermal spraying, factors such as the melting point and thermal conductivity of the material need to be comprehensively considered.
Secondly, when choosing the specific parameters for thermal spraying, you can refer to the following steps. First, clarify the functional requirements of the coating, such as wear resistance, corrosion resistance or insulation, etc. Secondly, select appropriate spraying materials and processes, such as flame spraying, plasma spraying or arc spraying, etc. Finally, through experiments and tests, the spraying parameters are optimized to achieve the best coating performance. Process parameters
I. Spray Distance
Impact: The evolution of particle speed and temperature during flight is directly affected by the flight distance.
2. Too short distance: Although the particles are hot, their speed has not reached the peak. When they impact the substrate, they may not deform sufficiently, and the heat input to the substrate is too large, resulting in overheating of the substrate and high stress on the coating.
3. Excessive distance: Particles cool and decelerate during flight. By the time they reach the matrix, they may have solidified or been traveling at too low a speed, resulting in poor bonding and high porosity.
3. Selection: There exists an "optimal window", which is usually determined through experiments to keep the particles in a "half-melted" or "fully melted" state with the highest speed at the moment of impact.
Ii. Powder Feed Rate
Impact: The amount of powder injected into the heat source within a unit of time.
2. Excessively high powder feeding rate: The powder cannot be fully heated and accelerated, resulting in a large number of unmelted particles and a decline in coating quality.
3. Low powder feeding rate: The powder may overheat and be burned away, resulting in low efficiency and possibly overheating of the substrate.
4. Selection: It must be matched with the energy input of the heat source to ensure that each particle can obtain sufficient thermal energy and kinetic energy.