Team Charter — Materials

Published

May 8, 2026

Mission

Defend the material choice for the copper combustion chamber, write the materials specification the vendor builds against, and review the vendor’s certification of the delivered part.

This is an engineering materials team, not a wet-chemistry team. Your job is to use chemistry to justify engineering choices, not to do electroplating at the bench.

Roles

Role Responsibility
Lead Schedules team work, attends cross-team standup
Deputy Lead Steps up if Lead absent; owns ICD interface checks
Safety Officer Owns Cu coupon handling + any reference-reaction demos
Analyst Drives the materials trade-study matrix
Specifier Drafts the vendor materials specification
Reviewer Reviews vendor’s material certificate when chamber is delivered

Deliverables

ID Deliverable Due Consumer
MA-D1 Materials trade-study matrix: Cu vs Al vs steel for the chamber, scored on melting point, thermal conductivity, density, ductility, machinability, cost, availability W2L4 Manufacturing (vendor RFQ), Lab Report 2
MA-D2 Cu justification memo: why copper is the chamber material — fail-soft reasoning, conductivity, Leap71 precedent, magnetron precedent W2L4 Lab Report 2
MA-D3 Galvanic-series demonstration: place Cu, Zn, Fe coupons in CuSO₄ (or dilute HCl) → show which displace Cu²⁺ and why Cu’s low reactivity is the reason it’s safe in contact with combustion products W2L3 Lab Report 1 (displacement coverage)
MA-D4 Vendor materials specification: copper grade (e.g. C10100 OFE), surface finish, wall thickness, certification required, traceability W3L12 Manufacturing (vendor RFQ), Vendor
MA-D5 Materials review of delivered part: cert against spec, inspection notes After delivery Lab Report 4, Phase 3 gate

Syllabus dot points owned

NSW Stage 5 Science:

  • CW2 single displacement (Cu²⁺ + Zn → Cu + Zn²⁺ in the galvanic demo)
  • CW5 corrosion and protection of metals (why Cu, why not Fe)
  • PW energy transfer (thermal conductivity discussion)
  • WS5.2 Predicting (Faraday-style atom-counting in galvanic demo)
  • WS6.3 Selecting equipment and materials
  • WS9 Communicating (the materials spec is a formal technical communication)

Weekly milestones

Week Milestone Evidence
W1 Cu galvanic series demo logged; cu, zn, fe coupons sourced from school lab stock MA-D3 + photos
W2 Trade-study matrix complete; Cu justification memo written MA-D1, MA-D2
W3 Vendor materials spec drafted MA-D4
W4 If Phase 3 part is delivered: certificate reviewed against spec MA-D5

Team-specific risks

  • Standard Stage 5 risks for Cu coupons in CuSO₄ or HCl — nitrile gloves + goggles
  • No project-specific elevated risks (electroplating dropped from scope)

The materials trade-study you defend

The trade-study matrix is the team’s headline intellectual output. Suggested structure — score each property low / medium / high or with real numbers where you have them:

Property Cu Al Steel Why it matters
Melting point (°C) 1085 660 1450 Fail-soft: lower-melting = safer fail mode
Thermal conductivity (W/m·K) 400 235 50 Heat moves into structure rather than building up
Density (g/cm³) 8.96 2.70 7.85 Mass affects load-cell range and shipping
Ductility High Medium Variable Deforms before fracturing → fail-soft
Machinability Medium High Hard for 3D print Vendor cost driver
3D-print AU vendors Few but exist Many Many Procurement lead time
Cost (small part AUD) $300-800 $150-400 $200-500 Quote-driven
Rocket-engineering precedent Leap71 aerospike; F-1 engine inner liner Falcon 9 tank; cheaper hobby motors Common but heavy Real-world legitimacy

Defend Cu in the memo. The other two are for comparison.

Cu galvanic series demo (replaces electroplating as the displacement coverage)

Single bench demonstration. ~15 minutes, standard Stage 5:

  1. Three test tubes, each with ~5 mL of 1 M CuSO₄ solution.
  2. Drop a clean Cu strip into the first, Zn strip into the second, Fe strip into the third.
  3. Wait 10 minutes; observe.
  4. Expected: Zn and Fe coat in red-brown Cu metal (displacement); Cu strip unchanged.
  5. Order metals from most reactive to least: Zn > Fe > Cu.
  6. Conclude: Cu is low on the activity series → it does not displace most other metals from solution AND most other metals don’t displace it → it is unreactive in contact with hot combustion products, which is exactly what we need for a chamber wall.

This is the displacement-reaction coverage for the syllabus. The chemistry justifies the engineering choice.

What you don’t do

  • You don’t electroplate (out of scope)
  • You don’t run an acid pickle line (out of scope)
  • You don’t dispose of plating waste (out of scope)
  • You don’t measure thermal properties of the delivered part (Heat Exchanger team via vendor telemetry)

Cross-team interfaces

  • To Manufacturing: vendor materials specification (MA-D4)
  • To Manufacturing + Rocket Chemistry: Cu reactivity argument (why it’s safe with combustion products)
  • From Manufacturing: chamber geometry envelope (sets the volume + mass calculations)
  • To Heat Exchanger: thermal conductivity values for use in reconciliation
  • To Comp Eng: copper thermal properties for the Rust crate (k, ρ, c_p)