| 摘要 |
<p>The substrate is heated to >500 degrees C, esp. to 800-1100 degrees C, for coating; and the coating process is interrupted at least once by cooling the substrate by >=30 degrees C., esp. by 50-100 degrees C. After the interruption, the substrate is reheated to the coating temp. before or during the renewal of the coating process. After cooling the substrate in a vacuum coating chamber (VCC), a special heater may be used to reheat the substrate; or the reheating may be achieved by reflected electrons from an electron beam evaporator in the VCC. Alternatively, during or after cooling in the VCC, the substrate may be transferred to a heating chamber, reheated, and then returned to the VCC for continuation of the coating process. Used for coating heat resistant alloys, esp. turbine blades, with a layer 150-400 x 10-3 mm thick, of CoCrAlY or NiCoCrAlY, where the interruption prevents continuous columnar crystals, gaps or defects from extending through the entire coating. The invention produces very homogeneous, dense, and adherent coatings.</p> |
