Metal plated additively manufactured plastic ACM shrouds with internal thermally adaptive structure

A method of forming a shroud for an air cycle machine (ACM), the method comprising:

• forming a shroud base having a plurality of discrete sections including:
• a first section defining connecting features for connecting with a fixed structure of the ACM;
• a second section that is positioned adjacent to a compressor rotor when installed in the ACM;
• and a third section that is disposed adjacent to a drive ring bearing when installed in the ACM, wherein forming the shroud base includes:
• printing, layer by layer, the shroud base, by printing first and second thermoplastic polymer surfaces, respectively from first and second thermoplastic polymers, that are disposed against each other, the first thermoplastic polymer surface having a first coefficient of thermal expansion (CTE), and the second thermoplastic polymer surface having a second CTE;
• forming a lower support section on the shroud base by printing, layer by layer, along the plurality of discrete sections of the shroud base a mixture of a third thermoplastic polymer and a catalyst formed with metal;
• and
• forming an upper support section on the shroud by depositing on the lower support section, along each of the discrete sections, via electrolysis deposition, a metallic coating, to thereby control thermal expansion and contraction of the shroud along the plurality of discrete sections, to thereby make the shroud.