Four Types of Engineering Materials Metals Alloys and Phase Diagrams Ferrous Metals Nonferrous Metals Ceramics Polymers Composites John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

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

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 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

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 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

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

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

Cu-Ni System Example Determine compositions of liquid and solid phases at an aggregate composition of 50% nickel and temperature of 1260oC (2300oF) ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

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 = John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

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

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

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

Figure 6.12 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

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

Plain Carbon Steels and Low Alloy Steels Low carbon steels - contain less than 0.20% C automobile sheetmetal parts Medium carbon steels - 0.20% 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

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

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

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

Cu-Ni System ©2007 John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing 3/e

SME Video John Wiley & Sons, Inc. M P Groover, Fundamentals of Modern Manufacturing

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

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