| 摘要 |
<p>Metal substrates, esp. ferrous alloys, are coated with free-flowing metal alloy powders carried by a gas (a) to the baking or coating zone, where the powder is sprayed onto the substrate without melting the substrate's surface. Gas (a) carrying powder is fed separately into the coating zone w.r.t. a steam of burner gas (b); and gas (a) does not increase the free oxygen content of the sec. flame. Gas (a) carrying the powder, is pref. fed in a conventional way along the axis of the autogenous flame obtd. from gas (b); and gas (a) is pref. CO2; an inert gas, e.g. Ar; or nitrogen. Conventional flame spraying methods produce coatings which lack smoothness and have inadequate hardness; moreover particles contg. e.g. carbides are oxidised and spraying losses occur. The invention avoids these problems.</p> |
