1. Four Types of Engineering Materials
Metals
Alloys and Phase Diagrams
Ferrous Metals
Nonferrous Metals
Ceramics
Polymers
Composites
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2. Why Metals Are Important
High stiffness and strength
alloyed for high rigidity, strength, and hardness
Toughness
capacity to absorb energy
Electrical conductivity
Thermal conductivity
conduct heat better than ceramics or polymers
Competitive cost
John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

3. Classification of Metals
Ferrous ‑ those based on iron
Steels and Cast irons
Nonferrous ‑ all other metals
Aluminum Magnesium
Copper Nickel
Titaniun Zinc
Lead Tin
Mmolybdenum Tungsten
Gold Silver
Platinum Others
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4. Metals and Alloys Pure elements (e.g., gold, silver, copper)
Enhanced properties obtained by alloying
increase strength
hardness
Alloy = mixture of metallic element with one or more other elements
Solid solutions
Intermediate phases
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5. Two Forms of Solid Solutions
Figure 6.1 Two forms of solid solutions: (a) substitutional solid solution, and (b) interstitial solid solution.
John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

6. Copper-Nickel Phase Diagram
Figure 6.2 Phase diagram for the copper‑nickel alloy system.
John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

7. Cu-Ni System Example
Determine compositions of liquid and solid phases at an aggregate composition of 50% nickel and temperature of 1260oC (2300oF)
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8. Inverse Lever Rule Proportion of liquid phase present is given by
L phase proportion =
Proportion of solid phase present is given by
S phase proportion =
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9. Tin-Lead Phase Diagram
Figure 6.3 Phase diagram for the tin‑lead alloy system.
John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

10. Iron-Carbon Phase Diagram
Ferrous Metals
Iron and carbon
Steel
0.02% to 2.1% carbon
Cast Iron
2.1% to 5% carbon
 = ferrite (BCC)
 = austenite (FCC)
Fe3C = Cementite
John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

11. Steel is an Alloy 0.02% and 2.11% carbon by weight
Includes other alloying elements:
Nickel Manganese
Chromium Molybdenum
Plain carbon steels
Low alloy steels
Stainless steels
Tool steels
John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

12. Figure Tensile strength and hardness as a function of carbon content in plain carbon steel (hot rolled).
John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

13. AISI-SAE Designation Scheme
4‑digit number system:
10XX
10 indicates plain carbon steel
XX indicates carbon % in hundredths of percentage points
Example
1020 steel contains 0.20% C
American Iron and Steel Institute (AISI)
Society of Automotive Engineers (SAE)
AISI 1020 or SAE 1020
John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

14. Plain Carbon Steels and Low Alloy Steels
Low carbon steels - contain less than 0.20% C
automobile sheetmetal parts
Medium carbon steels % to 0.50% C
crankshafts and connecting rods
High carbon steels - greater than 0.50% C
cutting tools and wear-resistant parts
Low alloy steels
additional alloying elements (up to 5%)
higher strength, hardness, hot hardness, wear resistance, toughness
heat treatment often required
John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

15. AISI-SAE Designation Scheme
4‑digit number system
YYXX
YY indicates alloying elements
XX indicates carbon % in hundredths of % points
Examples:
13XX - Manganese steel
20XX - Nickel steel
31XX - Nickel‑chrome steel
40XX - Molybdenum steel
41XX - Chrome‑molybdenum steel
John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

16. Stainless Steel (SS) Highly alloyed for corrosion resistance
Main alloying element is chromium (>15%)
Cr forms a thin impervious oxide film
protects surface from corrosion
Nickel (Ni) is another alloying ingredient
increase corrosion protection
Carbon to strengthen and harden SS
high C content reduces corrosion protection
chromium carbide forms
reduces available free Cr
John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

17. In-class example
For the copper‑nickel phase diagram in Figure 6.2, find the compositions of the liquid and solid phases for a nominal composition of 70% Ni and 30% Cu at 1371C (2500F).
Use the inverse lever rule to determine the proportions of liquid and solid phases present in the alloy.
John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

18. Cu-Ni System
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19. SME Video
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20. ASSIGNMENT – STUDENT MUST SHOW SOLUTION TO PROFESSOR DURING LAB PERIOD
Using the lead‑tin phase diagram in Figure 6.3, determine the liquid and solid phase compositions for a nominal composition of 40% Sn and 60% Pb at 204C (400F).
Use the inverse lever rule to determine the proportions of liquid and solid phases present in the alloy.
John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

21. Tin-Lead Phase Diagram
©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e