7 Materials Engineering Objectives Define materials engineering Identify
7 Materials Engineering
Objectives • • • Define materials engineering. Identify different types of materials. Describe a range of material properties. List examples of material tests. Describe nanotechnology. © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Materials Engineering • The understanding and modification of structure and properties of materials to improve the performance and processing of material. • Example- they may work in manufacturing to find the best ways to produce products using specific materials. An engineer may develop a better way to use plastics to make toys. © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
About Materials Engineering • Historical time periods based on materials – Stone Age – Bronze Age – Iron Age – Information Age (silicon and plastics) • Understanding of science is important • Design and development of new materials • Production using specific materials © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Education Typically Required • High school courses – Upper-level math (calculus and statistics) – Upper-level science (chemistry and physics) • College courses – Engineering design – Thermodynamics of materials – Structures of materials – Metallurgy • Internships © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Professional Organizations • ASTM-American Society for Testing and Materials – Develops material testing standards – Over 30, 000 members worldwide • Materials Information Society • Materials Research Society • NACE International(National Assoc. For Corrosion Engineers) • Other organizations for ceramics, plastics, and metals © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Principles of Materials Engineering • Broad field • Materials are used in every engineering field • All engineers must understand basic principles – Types of materials – Properties of materials © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Material Types • • Metals Ceramics Polymers Composites © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
The Four Types of Materials ARENA Creative/Shutterstock. com; kubais/Shutterstock. com; Evgeny Korshenkov/Shutterstock. com; noppharat/Shutterstock. com © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Metals • Have crystalline atomic structure – High material strength – Good conductors of heat and electricity – Malleable • • Inorganic material Most pure metals are natural Many are found in ore Commonly used in alloys © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Atomic Structure of Crystalline Materials Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Properties of Various Forms of Alloys Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Ceramics • Most have crystalline structure – Strong in compression – High melting temperature – Can retain heat well • • Brittle Good insulators Include clay, cement, many types of abrasives Some can become magnets © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Polymers • • Organic materials Noncrystalline Can be natural or synthetic Plastics are most common type – Lightweight but strong – Easy and fairly inexpensive to process – Have some negative environmental impacts – Thermoplastics and thermosets © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Atomic Structure of Noncrystalline Materials Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Thermoplastics and Thermosets Picsfive/Shutterstock. com; Barghest/Shutterstock. com; Claudio Divizia/Shutterstock. com; Big Pants Production/Shutterstock. com; Kletr/Shutterstock. com; Santhosh Kumar/Shutterstock. com © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Going Green Recycling Plastics • Saves use of oil and natural gas • Less plastics take up space in landfills • Society of Plastics Industry created codes – Include recycling symbol, number, and abbreviation – Useful to consumers who recycle • Over 82 million tons of materials are recycled per year in U. S. © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Composites • • Utilize advantages of several materials Each material can be identified Can be natural or synthetic Most consist of matrix and fiber – Matrix is main material – Fiber is strengthening material • Include wood, concrete, plywood, and fiberglass © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Other Materials • Fluids – Air and water – Many products rely on their use • Semiconductors – Can act as insulators or conductors – Used to create electronic components • Biomaterials – Can interact safely with human body – Used in medical applications © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Design Materials Symbols • Used in architectural design • Symbols for common building materials – Brick – Concrete – Cinder block • Symbols for insulation, glass, and metal • Allow designers and architects to include graphics of types of materials to be used © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Examples of Materials Symbols Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Material Properties • • Physical Mechanical Electrical Magnetic • • Chemical Thermal Optical Acoustical © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Physical Properties • • Can often be obtained using senses Include size, shape, look, feel, taste, and smell Some cannot be determined by senses Most commonly used is density – Mass per unit of volume – Often used to compare materials © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Mechanical Properties • How material behaves when force or load is applied • Understanding of stress is important – Can be applied through axis of material – Shear stress is not applied through axis – Causes strain on material • Compression strength and tensile strength • Elasticity • Plasticity © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
A Stress/Strain Diagram Goodheart-Willcox Publisher © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Electrical Properties • How a material behaves when electrically charged • Materials fall into one of three categories – Conductors – Insulators – Semiconductors • Conductivity • Resistivity © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Magnetic Properties • How a material behaves when within a magnetic field • Magnetic permeability – Measured in Henrys per meter – Impacted by temperature and distance from magnetic field – If it is high, material will allow magnetic flow © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Chemical Properties • • Changed by a chemical reaction Include flammability Include corrosion Often need to be controlled because they can be damaging to material © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Thermal Properties • • • How the material responds to heat Thermal conductivity Thermal resistance Thermal expansion Melting point © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Optical Properties • How light waves interact with material – How well material absorbs light – How well material reflects light – How well material transmits light • Reflected light gives material color • Transmission occurs when light is absorbed and reflected by transparent materials but still passes through materials © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Acoustical Properties • How sound waves interact with material – How well material absorbs sound – How well material reflects sound – How well material transmits vibration • Porous materials usually absorb sound • Smooth materials reflect sound in one direction • Rough materials reflect sound in many directions © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Material Engineering Applications • Material testing – Many companies specialize in specific materials – ASTM develops standards for testing • Nanotechnology – One nanometer is one billionth of meter – Has potentially exciting impacts © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Material Testing • Used for new materials when creating new products or improving existing products • Designer might try different formulation of existing material • Large industry • Categories of material tests – Destructive material tests – Nondestructive material tests © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Destructive Tests • Often used to test mechanical properties – Exert a force on material until it fails – Tensile tests – Compression tests – Fatigue tests • Often used to test chemical properties – Test material’s reaction to corrosion – Material exposed to saltwater © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Nondestructive Tests • • Used to inspect materials Used to look for flaws and defects Visual examinations, sometimes with dyes Some use waves – Radiography tests – Ultrasonic tests • Some use currents – Eddy current testing – Magnetic particle testing © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Potential Uses of Nanotechnology • For delivery of medicines directly to cancerous tumors • For creating microscopic computer chips • For manufacturing materials that repair and clean themselves © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Nanoparticles • Most basic components at nanoscale • Some materials demonstrate properties at nanoscale that are not present at larger scales • Products are being designed that utilize these properties © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Nanostructures • Nanowires – Designed to transmit light or electricity – Might be useful in computer circuits and lighting • Nanotubes – Cylindrical fullerenes with honeycomb pattern – Useful in electronics and structural applications • Buckyballs – Most perfectly round molecules – Useful as lubricants © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Nanotubes Tyler Boyes/Shutterstock. com © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Buckyballs Mark Lorch/Shutterstock. com © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
Materials Engineering in Action • Used to select or create most appropriate materials for engineered solution • Engineers must consider several key elements – Material function – Manufacturability – Cost – Safety © Goodheart-Willcox Co. , Inc. Permission granted to reproduce for educational use only.
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