Material Composition & Properties
Premium cobalt rods (ASTM F75) contain Co-28Cr-6Mo-0.25C with critical trace additions:
1.2% La for nano-oxide dispersion strengthening
0.05% Y grain boundary stabilization
Resulting in unmatched 980°C performance:
Creep Strength: 120 MPa (1,000h rupture)
Thermal Fatigue Resistance: >5,000 cycles (ΔT=800°C
Oxidation Rate: <0.5 g/m²·h (1,100°C/100h)
Precision Machining Protocol
Laser-assisted turning (LAT) parameters:
Preheating: 800W diode laser (650°C surface temp)
Cutting: VC=25m/min | ap=0.15mm | f=0.05mm/rev
Achieves surface integrity:
Residual stress: -120 MPa (XRD measurement)
Roughness: Ra 0.2μm (white light interferometry)
GE Aviation LEAP Engine Validation
|
Parameter |
Conventional |
Cobalt Rod Blades |
Improvement |
|---|---|---|---|
|
Turbine inlet temp |
1,450°C |
1,600°C |
+150°C |
|
Overhaul interval |
12,000h |
18,000h |
+50% |
|
Specific fuel consumption |
0.325 lb/lbf·hr |
0.305 lb/lbf·hr |
-6.2% |
