{
  "schemaVersion": "1.1",
  "runId": "orch-1771263706-c8a924bf",
  "agent": "tech-lead",
  "status": "complete",
  "result": "**Al 6061-T6 vs 7075-T6 for a Lightweight Bracket — Thermal & Structural Trade-offs**\n\n• **Strength-to-weight:** 7075-T6 is significantly stronger (UTS ~572 MPa, yield ~503 MPa) vs 6061-T6 (UTS ~310 MPa, yield ~276 MPa) at nearly the same density (~2.81 vs 2.70 g/cm³). For a weight-critical bracket, 7075 allows thinner sections and less material for the same load capacity.\n\n• **Thermal conductivity:** 6061-T6 has notably higher thermal conductivity (~167 W/m·K) compared to 7075-T6 (~130 W/m·K). If the bracket must conduct heat away (e.g., heat sink function or thermal path in an assembly), 6061 is the better choice. 6061 also has a slightly higher CTE (~23.6 vs ~23.2 µm/m·°C), though the difference is minor.\n\n• **Thermal stress risk:** In applications with significant temperature gradients or thermal cycling, the lower yield strength of 6061 means it reaches plastic deformation sooner under thermally-induced stresses. 7075's higher yield gives more margin against thermal distortion, but its lower ductility (~11% vs ~17% elongation) means less warning before fracture under combined thermal + mechanical loads.\n\n• **Recommendation:** Choose **7075-T6** when the bracket is purely structural and weight is the primary driver. Choose **6061-T6** when thermal management matters (heat dissipation, thermal path), when weldability is needed, or when cost is a concern (6061 is cheaper and easier to machine/weld). For thermally cycled environments with high structural demand, consider 7075 but add fatigue/fracture analysis due to its lower ductility.",
  "deliverable": {
    "type": "recommendation",
    "title": "Al 6061-T6 vs 7075-T6 Bracket Material Comparison",
    "path": null,
    "summary": "Structural and thermal trade-off summary for lightweight bracket material selection"
  },
  "artifacts": [],
  "confidence": "high",
  "notes": "Standard handbook values used. For precision-critical applications, verify properties against supplier certs for the specific temper and product form.",
  "timestamp": "2026-02-16T12:41:00-05:00"
}