Thermal spray process

       Thermal spray process



1. Sandblasting and texturing

The cleanliness after sandblasting should reach the highest cleanliness Sa3 specified in Chapter 3 of GB8923, which completely removes oxide scale, rust, dirt and other attachments. The roughness should reach about R2 75um.

1) The compressed air used for sandblasting must be dry, oil-free and water-free. (Friendly link www.lczhuzao.com)

2) Choose copper slag sand with an abrasiveness range of 0.5-2.0mm. (Friendly link www.sdcyxcl.com)

3) The requirements for abrasives must have sharp edges and corners, and keep them clean and dry. (Friendly link www.lccysy.com)

2. Arc spraying

Technical parameters of spraying zinc and spraying aluminum:

1) Compressed air working pressure: 0.6Mpa.

2) No-load voltage: aluminum spray: 25-28V; zinc spray: 20-22V.

3) Working current: 150-200A.

4) Spray distance: 200-250mm.

3. Air spray

Technical operating parameters:

1) The use pressure of compressed air is more than 0.5Mpa. (Friendly link www.lcabcd.com)

2) Oxygen pressure: 0.5Mpa.

3) Acetylene pressure: 0.08～0.1Mpa.

4. Coating inspection

According to GB9793-9794-88.

1. The coating thickness is generally controlled at about 0.2mm, which can be formulated according to user needs. It can also be sprayed with zinc and then sprayed with aluminum.

2. The surface of the coating must be uniform, and no peeling, bubbling, large molten droplets, cracks, blocks and other defects that affect the use of the coating are allowed.

3. Combination performance:

1) Use the cheque method.

2) Use the sample for tensile test.

3) Ball drop method: Use Φ40mm steel ball, drop it vertically from 1 meter, and see if the coating is damaged.

4. The corrosion resistance test of the coating: use the sample to do the salt spray test method or the salt water immersion method.