What principles should be followed in the structural design of the workpiece to be sprayed

       (1) Since the flight of thermal spray particles is a linear motion, any topographical design that may lead to masking blind spots, that is, topographical features that will hinder the corresponding surface to be sandblasted or sprayed, should be avoided.

    (2) For components or structures that are subject to thermal shock, rapid expansion and contraction, and strong vibration, when designing the coating system, the thermal properties of the base material, primer material, intermediate transition layer material and surface coating material should be fully considered. Physical properties (thermal expansion coefficient, thermal conductivity, specific heat capacity, melting point, etc.), especially the matching and transition of thermal expansion coefficients, to minimize thermal stress of the coating.

    (3) For the pretreatment and spraying of the inner cavity surface, the limitations imposed by "accessibility" and spraying distance requirements should be considered.

    (4) Considering factors such as spray guns, sandblasting guns and hard connecting hoses and spraying distances, any surface to be treated should have enough room for operation.

    (5) In the design of the substrate, the formation of narrow slits, blind slits, blind holes, deep grooves, sharp internal angles, etc. should be avoided as much as possible. Because this kind of topography is easy to form a "blind zone" that is neither suitable for pretreatment nor spraying.

    (6) The structural design should be conducive to making the sprayed beam energy at an angle of about 90 degrees with the surface to be sprayed, so that the kinetic energy of the sprayed particles hitting the surface of the substrate is maximized, and the angle of inclination cannot be less than 45 degrees.

    (7) From the perspective of corrosion protection, the structural design should minimize the possibility of localized pitting corrosion, and therefore should eliminate all topography that may promote the retention of moisture and powder deposits.

    (8) Appropriate entry holes and exhaust and dust removal holes should be designed for enclosed spaces such as the inner wall of the spraying box. Measures should be taken to remove dust remaining on the sprayed surface, otherwise it may become a source of corrosion.

    (9) According to the thickness of the designed coating, leave a margin for the workpiece to be sprayed