Silicide Coating for Aerospace Parts

Problem Statement
Design, fabricate and test an apparatus that applies a uniform silicide coating (R512E) to the inside surface of a niobium based alloy (C-103) thrust chamber and rocket nozzle.

Specifications
Our first specification involves achieving the desired thickness of 120 microns. Our method for ensuring a consistent coating thickness concerns the final mass of the piece. If the our procedure can produce coated nozzles with the same final mass within a certain tolerance, it follows that these nozzles with have coatings of the same thickness, assuming the coating is even across the piece.

Our second specification involves the visual quality of the coating. In order to assess how even the coating is, the nozzles will be visually observed and compared with the desired visual qualities supplied by our sponsors. These qualities are no running, no bare spots, and no clumps; basically a visually even and smooth coating on the nozzle.

Our final specification is being able to replicate the above qualities on nozzles of various sizes, from 10-28 cm. In order to achieve this, our apparatus will be adjustable in order to accommodate nozzles of various size and geometry.

Objective
The following is our Project Objective, as given by our sponsor:

"It is desirable to have a coating system that can accommodate a range of rocket nozzle sizes and produce a uniform coating thickness on the inside nozzle surface. Potential design direction include a fill and drain method where a fixture holds and seals a nozzle partly filled with glaze, while a computer controlled stage rotates and tilts the fixture in prescribed motion before draining. Glaze thickness can be estimated from weight addition and uniformity will be assessed by visual inspection."

Manipulate nozzles from 10 to 28 cm in length Uniform inside surface coatings free of drips and runs Simple, automated operation

Nozzle Machining






SolidWorks Nozzle Models
Small Nozzle

Medium Nozzle

Large Nozzle

Schematic of the Apparatus
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