61.1 THIN LAYER DEPOSITION
· Thin layers can be mixed into surfaces using electron and laser beams,
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1. A thin layer is deposited on a surface with other techniques,
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a) electrostatic vapor deposition
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b) a thin sheet is applied
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c) the material is delivered as the beams work
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2. A laser or electron beam melts the surface and mixes the two materials
· The rates can be greater than 1 m/s
· Advantages,
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- radiation penetration is shallow
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- no chemical contamination
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- no gas or jets to disturb molten surface
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- high precision for delivery
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- automation is possible
· Disadvantages,
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- high capitol cost
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- beams narrow, so multiple passes required (slow)