PCM Thermal Interface
Thermal Interface Materials Between PCM and Hot/Cold Side
The PCM thermal interface consists of conductive solid layers, specifically pyrolytic graphite sheets and indium foil, positioned between phase change material cells and equipment to maintain effective conductive heat transfer. Operating in the lunar vacuum requires solid, vacuum-rated materials to eliminate the outgassing risks associated with standard thermal greases. Furthermore, recurring thermal cycling stresses mechanical joints, requiring 50 µm of physical compliance to preserve continuous contact across rigid interfaces. Delivering a thermal conductivity of 5 W/(m·K) at a total mass of 2 kg, these passive materials consume zero power and provide a 25-year operational lifetime with a mean time between failures of 1,000,000 hours.
Thermal interface materials (graphite pads, indium foil) between PCM cells and equipment ensuring effective heat transfer.
Purpose
Thermal interface materials (graphite pads, indium foil) between PCM cells and equipment ensuring effective heat transfer.
Context
Child of L2-PTC-PCM within the Lunar Ark system
Principles
- ▸Graphite pad (Pyrolytic graphite sheet) for compliant interface
- ▸Indium foil for high-conductivity rigid joints
- ▸Thermal grease alternatives (vacuum-rated)
- ▸Coordinated with L3-ESS-LITH-COOL gap pads
- ▸Long-life solid TIM preferred
Typical implementations
- ▸Industrial TIM (Bergquist, T-Global)
- ▸Aerospace thermal interface materials
- ▸Electronic packaging TIM
Lunar considerations
- ▸Vacuum-rated TIM (no outgassing)
- ▸Long-life solid pads preferred over grease
- ▸Compliant interface accommodates thermal cycling
Specifications
Functional
| primary function | Thermal interface materials (graphite pads, indium foil) between PCM cells and equipment ensuring effective heat transfer. |
| thermal conductivity w per mk | 5 |
| compliance um | 50 |
Physical
| mass kg | 2 |
| materials | Pyrolytic graphite sheet, Indium foil, Vacuum-grade silicone grease |
| vacuum compatibility | True |
Operational
| power consumption w | 0 |
| thermal range c | -40, 70 |
| lifetime years | 25 |
| mtbf hours | 1000000 |
Interfaces
Provides
- Thermal coupling to PCM cells
Requires
- TIM stock
Cite this entry
Lunar Ark Codex. "PCM Thermal Interface" (L3-PTC-PCM-INTF). Retrieved 10 September 2026, from https://lunarark.com/entry/L3-PTC-PCM-INTF
Licensed CC-BY-SA 4.0. You may reuse and adapt this entry with attribution, under the same licence.