Metal plated additively manufactured plastic ACM housings with internal thermally adaptive structure
A method of forming a housing for an ACM, having steps of: forming a base: a first section adjacent to a seal of an ACM compressor rotor when installed; a second section that is fixed to an ACM forward frame member when installed; a third section adjacent to a bearing and sleeve disposed around an ACM compressor rotor shaft when installed, forming the base includes: printing thermoplastic polymer surfaces from thermoplastic polymers that are disposed against each other, the thermoplastic polymer surface having differing CTEs; forming a lower support section on the base by printing, layer by layer, along the plurality of discrete sections of the base a mixture of a third thermoplastic polymer and a catalyst formed with metal; and forming an upper support section on the housing by depositing on the lower support section, along each of the discrete sections, via electrolysis deposition, a metallic coating.
1 . A method of forming a housing for an air cycle machine (ACM), the method comprising:
forming a housing base having a plurality of discrete sections including: a first section that is adjacent to a seal of a compressor rotor when installed in the ACM; a second section that is fixed to a forward frame member when installed in the ACM; a third section that is adjacent to a bearing and sleeve disposed around a compressor rotor shaft when installed in the ACM,
wherein forming the housing base includes:
printing, layer by layer, the housing 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 housing base by printing, layer by layer, along the plurality of discrete sections of the housing base a mixture of a third thermoplastic polymer and a catalyst formed with metal; and
forming an upper support section on the housing 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 housing along the plurality of discrete sections, to thereby make the housing.
2 . The method of claim 1 , wherein the first and second CTEs differ from each other.
3 . The method of claim 1 , wherein:
forming the housing base includes printing, layer by layer, a lattice of beads, wherein each of the beads has an outer surface formed by the first thermoplastic polymer surface and an inner surface formed by the second thermoplastic polymer surface, and wherein a void is formed in a center of each of the beads.
4 . The method of claim 3 , wherein:
the outer surface has first thickness and the inner surface has a second thickness that is greater than the first thickness.
5 . The method of claim 4 , wherein:
forming the housing base includes printing the outer surface or the inner surface of each bead to include a first fiber having a fourth CTE that differs from the first and second CTEs.
6 . The method of claim 5 , wherein:
forming the housing base includes printing the outer surface to include the first fiber having the fourth CTE and the inner surface to include a second fiber that that has a fifth CTE that differs from the first, second and fourth CTEs.
7 . The method of claim 6 , wherein the first and second CTEs, other than the fourth and fifth CTEs, are the same as each other.
8 . The method of claim 6 , wherein the first fiber and the second fiber differ from each other, each being one of metallic, carbon or Kevlar fibers.
9 . The method of claim 3 , wherein: forming the housing base includes printing, layer by layer, a reinforcing fibrous string on each bead, wherein the reinforcing fibrous string extends linearly across the bead, over the void of the bead.
10 . The method of claim 3 , wherein forming the housing base includes:
printing the first thermoplastic polymer surface to provide a first CTE gradient; and
printing the second thermoplastic polymer surface to provide a second CTE gradient.
11 . The method of claim 10 , wherein:
the first and second CTE gradients change in a thickness direction of the housing base, and at an interface between the first and second thermoplastic polymer surfaces, the first and second CTEs are the same as each other; or
the first and second CTE gradients change in a circumferential direction, and at the interface between the first and second thermoplastic polymer surfaces, the first and second CTEs are the same as or differ from each other.
12 . The method of claim 1 , wherein:
forming the housing base includes printing, layer by layer, a continuous structure having voids, where the continuous structure is formed by the first thermoplastic polymer surface, and each of the voids is lined with the second thermoplastic polymer surface.
13 . The method of claim 1 , wherein the first and second thermoplastic polymer surfaces are the same as each other.
14 . The method of claim 1 , wherein the first thermoplastic polymer surface is Acrylonitrile butadiene styrene (ABS).
15 . The method of claim 1 , wherein the catalyst is palladium (II) chloride (PdCl 2 ).
16 . The method of claim 1 , including utilizing stereolithography (SLA) or fused deposition modeling (FDM).
17 . The method of claim 1 , wherein:
forming the housing base includes printing, layer by layer, an outer surface formed by the first thermoplastic polymer surface and an inner surface formed by the second thermoplastic polymer surface.
18 . The method of claim 17 , wherein:
forming the housing base includes printing the outer surface or the inner surface to include a first fiber having a fourth CTE that differs from the first and second CTEs.
19 . The method of claim 18 , wherein:
forming the housing base includes printing the outer surface to include the first fiber having the fourth CTE and the inner surface to include a second fiber that that has a fifth CTE that differs from the first, second and fourth CTEs.