C Muhlstein 2007 MATSE 259 Spring 2007 C

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein MATSE 259 Lecture 2: Introduction to Aluminum Alloys Christopher L. Muhlstein, Ph. D. Department of Materials Science and Engineering The Pennsylvania State University Park, PA The contents of this lecture are protected under U. S. copyright law and should not be duplicated or redistributed for commercial purposes. 1

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Last Lecture • Fundamentals of materials science and engineering • Classes of materials properties • Three classes of materials • Steel nomenclature 2

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Lecture 2: Key Concepts and References • Aluminum alloy nomenclature • Introduction to phases • Reference (Callister) – sects. 3. 12, 4. 3, 5. 1 – pps. 261 -262 – chapter 6 3

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Al Structural Alloys Lotus Elise 190 hp 1984 lbs 0 -60 mph - 4. 9 sec top speed - 150 mph 27 mpg highway $46 K 4

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Automotive Application of Al Alloys • Lotus versatile vehicle architecture system (VVA) • Almost all “aluminum high pressure diecastings, stampings, and extrusions Advanced Materials & Processes, July 2005, p 29 5

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Which “aluminum” is it? 1050 3003 5052 6010 7072 1145 3004 5083 6061 7075 2014 3105 5154 6262 7175 2024 4032 5182 6463 7178 2219 4043 5262 7005 7475 2618 5005 5652 7050 7229 6

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Aluminum Alloy Overview • • • Low density (~34% of steel) High thermal and electrical conductivity Corrosion resistant in ambient air Low melting point (660°C) Modified mechanical properties via cold work, alloying, and heat treating 7

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Aluminum Alloy Nomenclature • Aluminum Association Number • 4 digit number + temper designation (letter and sometimes numbers) • Wrought vs. cast designation – 4 digits, no punctuation (e. g. 6061) – 4 digits, decimal point between last two digits (e. g. 295. 0) 8

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Wrought Aluminum Alloy Nomenclature • First digit indicates alloy group – 1 XXX Aluminum ≥ 99. 00% – 2 XXX Copper – 3 XXX Manganese – 4 XXX Silicon – 5 XXX Magnesium – 6 XXX Magnesium + Silicon – 7 XXX Zinc – 8 XXX other elements – 9 XXX Unused series 9

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein 1 XXX Series Wrought Aluminum Alloys • 10 XX are unalloyed • Last two digits give minimum aluminum percentage – 1035 contains 99. 35% aluminum • The second digit indicates control over specific impurities (e. g. silicon) 10

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Cast Aluminum Alloy Nomenclature • First digit indicates alloy group – – – – 1 XX. X Aluminum >99. 00% 2 XX. X Copper 3 XX. X Silicon with added copper and/or magnesium 4 XX. X Silicon 5 XX. X Magnesium 7 XX. X Zinc 8 XX. X Tin 9 XX. X Other elements • Second two digits identify specific alloy • Last digit indicates casting (0) or ingot (1) • Letter may be appended, in some cases 11

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein 1 XX. X Series Cast Aluminum Alloys • Second two digits indicate minimum aluminum percentage – 135. 0 Aluminum is a 99. 35% aluminum casting – 135. 1 Aluminum is a 99. 35% aluminum ingot 12

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Material Structure • Amorphous materials • Single crystal materials • Polycrystalline materials • Grain boundaries • Isotropic and anisotropic properties Small crystalline nuclei Growth of crystallites Solidified Optical micrograph Schematic of stages of solidification of a polycrystalline material; the square grids depict unit cells Callister, Materials Science and Engineering: 13 An Introduction (2003)

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Structural Materials are Complicated! • Names? • Crystal structure(s)? • Microstructure? Transmission electron micrograph of 7150 -T 651 Optical micrographs of various cast irons. Callister, Materials Science and Engineering: 14 An Introduction (2003)

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Microstructural Evaluation (Optical) • Optical Microscopy – Grind – Polish – Etch/stain/anodize – Image 15

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Etchants Reveal Microstructure Polished Gray Iron Polished and Etched Gray Iron 16

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Wrought Aluminum Microstructures 10% Reduction 40% Reduction 5457 -O plate, Barker’s reagent 80% Reduction ASM, Metals Handbook Volume 9 (1995) 17

© C. Muhlstein, 2007 MATSE 259 Spring 2007, C. Muhlstein Steel Microstructures Pearlite Tempered Martensite Spheroidite Callister, Materials Science and Engineering: 18 An Introduction (2003)