Appendice Caratteristiche Dettagliate dei Materiali Utilizzati A.1 Materiale AISI 9840 UNI 38NiCrMo4 AISI 9840 Steel, 650 C (1200 F) temper, 25 mm (1 in.) round Material Notes: Quenched, 540 C temper, 525 C nitride for 40 hours with 20-30% ammonia dissociation, hardness of 88 HR15N case hardness at 0.635-0.762 mm nitrided case depth Density 7.87 g/cc 0.284 lb/in³ Hardness, Brinell 280 280 Hardness, Knoop 306 306 Hardness, Rockwell B 99 99 Hardness, Rockwell C 35 35 Hardness, Vickers 295 295 Tensile Strength, Ultimate 965 MPa 140000 psi Tensile Strength, Yield 825 MPa 120000 psi Elongation at Break 19.0 % 19.0 % Modulus of Elasticity 200 GPa 29000 ksi Bulk Modulus 140 GPa 20300 ksi Poissons Ratio 0.290 0.290 Machinability 70 % 70 % Shear Modulus 80.0 GPa 11600 ksi Electrical Resistivity 0.0000174 ohm-cm 0.0000174 ohm-cm CTE, linear 11.5 µm/m- C @Temperature 20.0 C 6.39 µin/in- F @Temperature 68.0 F 169
12.2 µm/m- C @Temperature 250 C 6.78 µin/in- F @Temperature 482 F 13.9 µm/m- C @Temperature 500 C 7.72 µin/in- F @Temperature 932 F 14.7 µm/m- C @Temperature 1000 C 8.17 µin/in- F @Temperature 1830 F Specific Heat Capacity 0.472 J/g- C 0.113 BTU/lb- F Thermal Conductivity 51.9 W/m-K 360 BTU-in/hr-ft²- F Carbon, C 0.380-0.430 % 0.380-0.430 % Chromium, Cr 0.80 % 0.80 % Iron, Fe 96.0 % 96.0 % Manganese, Mn 0.80 % 0.80 % Molybdenum, Mo 0.25 % 0.25 % Nickel, Ni 1.0 % 1.0 % Phosphorous, P <= 0.035 % <= 0.035 % Silicon, Si 0.230 % 0.230 % Sulfur, S <= 0.040 % <= 0.040 % 170
A.2 Materiale AISI 8740 UNI 40NiCrMo2 AISI 8740 Steel, normalized 870 C (1600 F), 50 mm (2 in.) round Material Notes: Normalized at 870 C, air cooled, 50 mm round Density 7.85 g/cc 0.284 lb/in³ Hardness, Brinell 262 262 Hardness, Knoop 287 287 Hardness, Rockwell B 98 98 Hardness, Rockwell C 26.0 26.0 Hardness, Vickers 276 276 Tensile Strength, Ultimate 910 MPa 132000 psi Tensile Strength, Yield 800 MPa 116030 psi Elongation at Break 16.7 % 16.7 % Modulus of Elasticity 205 GPa 29700 ksi Bulk Modulus 140 GPa 20300 ksi Poissons Ratio 0.290 0.290 Machinability 65 % 65 % Shear Modulus 80.0 GPa 11600 ksi Electrical Resistivity 0.0000234 ohm-cm 0.0000234 ohm-cm Specific Heat Capacity 0.475 J/g- C 0.114 BTU/lb- F Thermal Conductivity 46.6 W/m-K 323 BTU-in/hr-ft²- F Carbon, C 0.380-0.430 % 0.380-0.430 % Chromium, Cr 0.50 % 0.50 % Iron, Fe 97.0 % 97.0 % Manganese, Mn 0.880 % 0.880 % Molybdenum, Mo 0.25 % 0.25 % Nickel, Ni 0.55 % 0.55 % Phosphorous, P <= 0.035 % <= 0.035 % Silicon, Si 0.230 % 0.230 % Sulfur, S <= 0.040 % <= 0.040 % 171
A.3 Materiale Ti6Al4V Material Notes: Titanium Ti-6Al-4V (Grade 5), Annealed Information provided by Allvac and the references. Annealing Temperature 700-785ºC. Alpha- Beta Alloy. Applications: Blades, discs, rings, airframes, fasteners, components. Vessels, cases, hubs, forgings. Biomedical implants. Biocompatibility: Excellent, especially when direct contact with tissue or bone is required. Ti- 6Al-4V's poor shear strength makes it undesirable for bone screws or plates. It also has poor surface wear properties and tends to seize when in sliding contact with itself and other metals. Surface treatments such as nitriding and oxidizing can improve the surface wear properties. 4 other heat treatments of this alloy are listed in MatWeb. Density 4.43 g/cc 0.160 lb/in³ Hardness, Brinell 334 334 Hardness, Knoop 363 363 Hardness, Rockwell C 36 36 Hardness, Vickers 349 349 Tensile Strength, Ultimate 950 MPa 138000 psi Tensile Strength, Yield 880 MPa 128000 psi Elongation at Break 14.0 % 14.0 % Reduction of Area 36.0 % 36.0 % Modulus of Elasticity 113.8 GPa 16510 ksi Compressive Yield Strength 970 MPa 141000 psi Notched Tensile Strength 1450 MPa 210000 psi Ultimate Bearing Strength 1860 MPa 270000 psi Bearing Yield Strength 1480 MPa 215000 psi Poissons Ratio 0.342 0.342 Charpy Impact 17.0 J 12.5 ft-lb Fatigue Strength 240 MPa 34800 psi 510 MPa 74000 psi Fracture Toughness 75.0 MPa-m½ 68.3 ksi-in½ Shear Modulus 44.0 GPa 6380 ksi Shear Strength 550 MPa 79800 psi Electrical Resistivity 0.000178 ohm-cm 0.000178 ohm-cm Magnetic Permeability 1.00005 1.00005 Magnetic Susceptibility 0.00000330 0.00000330 CTE, linear 8.60 µm/m- C @Temperature 20.0-100 C 4.78 µin/in- F @Temperature 68.0-212 F 172
9.20 µm/m- C @Temperature 20.0-315 C 5.11 µin/in- F @Temperature 68.0-599 F 9.70 µm/m- C @Temperature 20.0-650 C 5.39 µin/in- F @Temperature 68.0-1200 F Specific Heat Capacity 0.5263 J/g- C 0.1258 BTU/lb- F Thermal Conductivity 6.70 W/m-K 46.5 BTU-in/hr-ft²- F Melting Point 1604-1660 C 2919-3020 F Solidus 1604 C 2919 F Liquidus 1660 C 3020 F Beta Transus 980 C 1800 F Aluminum, Al 6.0 % 6.0 % Iron, Fe <= 0.25 % <= 0.25 % Oxygen, O <= 0.20 % <= 0.20 % Titanium, Ti 90.0 % 90.0 % Vanadium, V 4.0 % 4.0 % 173