Material selection for different components
- 1. MATERIAL SELECTION IN MECHANICAL ENGINEERING 01. Performance index = 𝜎 ƥ Figure 01: Material property table for question 1
- 2. Table 01: Material properties for selected materials for question 1 Medium carbon steel is used to design because it had high performance index and low cost Material Strength (MPa) Density (Kg/m3 ) Performance index (m2 /s2 )x106 Cost SLR/Kg Remarks Wrought Precipitation Hardened Stainless Steel 1007.5 7.8 129.17 243.7 good corrosive resistence/expensive Nodular (spheroidal, ductile) Cast Iron 502.5 7.15 70.28 40.6 low cost Cast ferritic stainless steel, ASTM CC-50, low nickel 447.5 7.525 59.47 139.3 low ductility Medium Carbon Steel 1030 7.85 131.21 40.6 high strength/low cost Wrought Ferritic Stainless Steel 435 7.65 56.86 208.9 expensive
- 3. 02. Performance index = 𝜎 3 2 𝐸 Figure 02: Material property table for question 2
- 4. Table 02: Material properties for selected materials for question 2 Material Strength Youngs modulus Performance index Relative cost Polypropylene (PP) - 20% CaCO3 23 2000 0.055 75.4 Polytetrafluoroethylene (PTFE) GF1 (PTFE+25% Glass Fibre) 20 1400 0.064 986.5 Chloro TriFluoro Ethylene (CTFE) 23 1600 0.069 3597 Ethylene TetraFluoro Ethylene (ETFE) 26 1400 0.095 1972.5 Polypropylene (PP) - 20% Talc 28.5 2300 0.066 86.6 Polytetrafluoroethylene (PTFE) GF1 (PTFE+25% Glass Fibre) is selected for the designing though it had somewhat high cost because for safety proposes Material Strength (MPa) Young’s modulus (GPa) Performance index (MPa0.5 )x10-3 cost (SLR/Kg) Remarks Polypropylene (PP) - 20% CaCO3 23 2000 0.055 75.4 Use as coatings Polytetrafluoroethylene (PTFE) GF1 (PTFE+25% Glass Fibre) 20 1400 0.064 986.5 Use for non-stick applications Chloro TriFluoro Ethylene (CTFE) 23 1600 0.069 3597 High Chemical resistivity Ethylene TetraFluoro Ethylene (ETFE) 26 1400 0.095 1972.5 Use as film Polypropylene (PP) - 20% Talc 28.5 2300 0.066 86.6 Us for fiber reinforcement
- 5. 03. Performance indices M1 = 𝐾𝐼𝐶 M2 = 𝐾 𝐼𝐶 𝜎 𝑓 M3 = 𝐾𝐼𝐶 2 𝜎 𝑓 M4 = 𝜎𝑓
- 6. Figure 03: Material property chart for question 3 Table 03: Material properties for selected materials for question 3 Wrought Ferritic Stainless Steel is selected for the design because it had good PI and good thermal properties
- 7. Material Fracture thougness(PI1) Strength(PI4) Performance index 2 Performan Wrought Ferritic Stainless Steel 100.5 435 0.231 23.22 Low Carbon Steel 61.5 322.5 0.191 11.73 Cast Austenitic Stainless Steel 141.5 330.5 0.428 60.58 Wrought Precipitation Hardened Stainless Steel 102.5 1007.5 0.102 10.43 Cast Duplex Stainless Steel 100.5 510 0.197 19.80 Material Fracture toughness(PI1) (MPa.m0.5 ) Strength(PI4) (MPa) Performance index 2 (m0.5 ) Performance index 3 (MPa.m) Cost (SLR/Kg) Remarks Wrought Ferritic Stainless Steel 100.5 435 0.231 23.22 208.5 Good thermal properties Low Carbon Steel 61.5 322.5 0.191 11.73 40.5 Low PI Cast Austenitic Stainless Steel 141.5 330.5 0.428 60.58 324.9 Expensive Wrought Precipitation Hardened Stainless Steel 102.5 1007.5 0.102 10.43 243.5 Expensive/Corrosive resistance Cast Duplex Stainless Steel 100.5 510 0.197 19.80 231.5 Good corrosive resistance
- 9. Figure 04: Material property chart for question 4 Table 04: Material properties for selected materials for question 4 Material Thermal diffusivity Thermal conductivity Performance index Relative cost Medium Density Wood (Transverse) (0.45-0.85) 0.0000001245 0.1395 0.002529 493 Common Hard Brick 0.0000006231 0.9 0.000877 63 Cement 0.0000003228 0.85 0.000668 8 Normal Density Concrete 0.0000006678 1.65 0.000495 4.5 Granite 0.0000012773 2.85 0.000397 203 Common hard brick is selected for the design because it’s low cost and ,thermal conduction and easiness of manufacture Material Thermal diffusivity (m2 s) Thermal conductivity (W/m.k) Performance index (s0.5 /W.k) cost (SLR/KG) Remarks Medium Density Wood (Transverse) (0.45-0.85) 0.0000001245 0.1395 0.002529 493 Flammable/Expensive Common Hard Brick 0.0000006231 0.9 0.000877 63 Low thermal conductivity Cement 0.0000003228 0.85 0.000668 8 High thermal expansion Normal Density Concrete 0.0000006678 1.65 0.000495 4.5 High thermal expansion Granite 0.0000012773 2.85 0.000397 203 Expensive
- 10. 05.
- 11. Performance index = σ2 E Figure 05: Material property chart for question 5 Table 05: Material properties for selected materials for question5
- 12. Material Strength Youngs modulus Performance index Relative cost Wrought Ferritic Stainless Steel 435 200 0.946 208.9 Nodular Graphite Cast Iron 205 117.5 0.358 59 Blackheart Malleable Cast Iron 224.5 170 0.296 43.1 Nodular (spheroidal, ductile) Cast Iron 502.5 172.5 1.464 40.6 Cast Ferritic Stainless Steel 430 200 0.925 139 Nodular (spheroidal, ductile) Cast Iron is selected for the design because it had good PI and low cost. Material Strength (MPa) Young’s modulus (GPa) Performance index (MPa) Cost (SLR/Kg) Remarks Wrought Ferritic Stainless Steel 435 200 0.946 208.9 Chemical and corrosive resistance Nodular Graphite Cast Iron 205 117.5 0.358 59 use as gas manifolds Blackheart Malleable Cast Iron 224.5 170 0.296 43.1 not good corrosive resistance Nodular (spheroidal, ductile) Cast Iron 502.5 172.5 1.464 40.6 Low cost/ high PI Cast Ferritic Stainless Steel 430 200 0.925 139 Excellent corrosive resistance
- 13. 6.1 Performance index = E 1 2 Cv,R Figure 06: Material property chart for question 6.1
- 14. Table 06: Material properties for selected materials for question6.1 Material Youngs Modulus Cost Performance index Remarks Low Alloy White Cast Iron 185 34.8 0.3908 Good abration resis Wrought Aluminium Alloy 75 168 0.0515 Light weight Low Carbon Steel 210 40.5 0.3578 Used in engineering applications Wrought Ferritic Stainless Steel 200 208.5 0.0678 Expensive Cast ferritic stainless steel, ASTM CC-50, low nickel 200 139 0.1017 Low nickle content Low Carbon steel is selected for design because of its High young’s modulus and low cost. Material Young’s Modulus (GPa) Cost (SLR/Kg) Performance index (GPa.Kg/SLR) Remarks Low Alloy White Cast Iron 185 34.8 0.3908 Good abrasion resistance Wrought Aluminum Alloy 75 168 0.0515 Light weight Low Carbon Steel 210 40.5 0.3578 Used in engineering applications Wrought Ferritic Stainless Steel 200 208.5 0.0678 Expensive Cast ferritic stainless steel, ASTM CC-50, low nickel 200 139 0.1017 Low nickel content
- 15. 6.2
- 16. Performance index = 𝜎 𝑓 2 3 𝐶 𝑉,𝑅 Figure 07: Material property chart for question 6.2 Table 07: Material properties for selected materials for question6.2
- 17. Material Strength Cost Performance index Remarks Low Alloy White Cast Iron 345 34.8 1.4135 Good abration re Wrought Aluminium Alloy 270 168 0.2487 Light weight Low Carbon Steel 322.5 40.5 1.1612 Used in engineer applications Wrought Ferritic Stainless Steel 435 208.5 0.2754 Low PI Cast ferritic stainless steel, ASTM CC-50, low nickel 447.5 139 0.4209 Low nickle conte Low Carbon steel is selected for the design because it had high PI and low cost 6.3 According to the results in 6.1 and 6.2 Low Carbon steel is suitable for low cost, stiff and strong beam Abbreviation Material Strength Cost Performance index Remarks Low Alloy White Cast Iron 345 34.8 1.4135 Good abrasion resistance Wrought Aluminum Alloy 270 168 0.2487 Light weight Low Carbon Steel 322.5 40.5 1.1612 Used in engineering applications Wrought Ferritic Stainless Steel 435 208.5 0.2754 Low PI Cast ferritic stainless steel, ASTM CC-50, low nickel 447.5 139 0.4209 Low nickel content
- 18. SLR – Sri Lankan rupees