ME361 Materials Science and Engineering PDF

ME361 Materials Science and Engineering Engr. Marlowe Jay V. Dignos Instructor Engr. Marlowe Jay...

ME361 Materials Science and Engineering Engr. Marlowe Jay V. Dignos Instructor Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  ME361 Course Learning Outcomes Evaluate the types, properties and characteristics of engineering materials. Identify the different new engineering materials and their industrial usage. Evaluate the behavior of materials subject to different kinds of testing. Appreciate the importance of materials science and engineering in all aspects of life. Engr. Marlowe Jay V. Dignos, M.S  ME361 Module 1 1.1. Historical Perspective 1.2. Materials Science and Engineering 1.3. Why Study Materials Science and Engineering 1.4. Classification of Materials 1.5. Advanced Materials 1.6. Modern Material Needs 1.7. Chemical Composition of Engineering Materials Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.1. Historical Perspective Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.1. Historical Perspective Every segment of our everyday lives is influenced to one degree or another by materials The development and advancement of societies have been intimately tied to the people’s ability to produce and manipulate materials to fill their needs. Early civilizations have been designated by the level of their materials development (Stone Age, Bronze Age, Iron Age) Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.1. Historical Perspective Evolution of Materials Index basis Stone and bronze age by Archeologist 1960s by the teaching hours in UK and US Univeristies 2020 predictions of material usage in automobiles by manufacturers Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.1. Historical Perspective Stone Age (15000-2000 BC) Stone tools, woods, bones Igneous and metamorphic rocks (strong materials) Bronze Age (3500-500 BC) This period known as “metal working” Initially “Copper” but malleable and not that strong Adding copper to another element will produce bronze Iron Age (3000 years ago until today) Begun the industrial revolution Need for transportation- automobile, railways and even airplanes Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.1. Historical Perspective Industrial Evolution Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.1. Historical Perspective Modern Era: Advance Materials Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.2. Materials Science and Engineering Materials Science and Engineering substance or involves investigating involves designing mixture of the relationships that or engineering the substances that exist between the structure of a constitutes an structures and material to produce object properties of a predetermined set Inanimate materials of properties materials Physical Sciences Solid materials Solid state chemistry Solid state Physics Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.2. Materials Science and Engineering Materials Science Materials Engineering Answers the question Why Designing the structure of a materials have their material to produce a properties? predetermined set of Materials Scientist develop properties or synthesize new Materials Engineer create new materials products or systems using existing materials and/or to develop techniques for processing materials Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.2. Materials Science and Engineering Structure of Materials arrangement of its internal components Subatomic structure involves electrons within the individual atoms, their energies and interactions with the nuclei. Atomic structure relates to the organization of atoms to yield molecules or crystals Microstructure those structural elements that are subject to direct observation using some type of microscope Macrostructure structural elements that may be viewed with the naked eye Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.2. Materials Science and Engineering Properties of Materials trait in terms of the kind and magnitude of response to a specific imposed stimulus Mechanical (Modulus of elasticity, Stress, hardness) Electrical (Electrical conductivity, capacitance) Thermal (Thermal conductivity, specific heat, coeff. thermal expansion) Magnetic (Magnetization, susceptibility) Optical (Reflectivity, refraction index) Deteriorative (corrosion resistance) Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.2. Materials Science and Engineering Materials Paradigm the core of the discipline of materials science and engineering Materials Paradigm viewed as a systematic procedure Materials Paradigm viewed as a systematic framework (interrelationship) Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.3. Why Study Materials Science and Engineering? Cause of failure: Brittle material usage which was thought to be ductile The failure of Liberty ship S.S. Schenectady in 1943 Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.3. Why Study Materials Science and Engineering? provide a barrier to the passage of carbon dioxide, which is under pressure in the container; be nontoxic, unreactive with the beverage, and, preferably be recyclable; be relatively strong, and capable of surviving a drop from a height of several feet when containing the beverage; be inexpensive and the cost to fabricate the final shape should be relatively low; if optically transparent, retain its optical clarity; and capable of being produced having different colors and/or able to be adorned with decorative labels. Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.3. Why Study Materials Science and Engineering? Criteria for Material Selection The in-service conditions must be clearly defined The deterioration of material properties that may occur during service The cost effectiveness or economics Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.4. Classification of Materials Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.4. Classification of Materials 1.4.1. Metals Stiff High elastic moduli When pure are soft and easily deformed Can be made strong by alloying and by mechanical and heat treatment Remain ductile allowing them to be formed by deformation processes Prey to fatigue Least resistant to corrosion Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.4. Classification of Materials 1.4.1. Metals Iron/Steel - used for strength critical applications​. Aluminum - easy to form, readily available, inexpensive, and recyclable.​ Copper - high electrical and thermal conductivity, high ductility, and good corrosion resistance.​ Titanium - strength in higher temperature (~1000° F) application, when component weight is a concern, good corrosion resistance​ Nickel – good corrosion resistance,​ higher temperatures applications ​ (~1500 2000° F), ​ Refractory – highest temperature ​ applications (>2000°F) ​ Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.4. Classification of Materials 1.4.1.1. Metal alloys Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.4. Classification of Materials 1.4.2. Ceramics Typically made from clay that has been subject to high temperatures mechanical properties: brittle, hard, strong, durable, inert, have high melting points commonly used in glass, windows, pottery, tiles, and porcelain Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.4. Classification of Materials 1.4.2. Ceramics-glass noncrystalline (“amorphous”) solids​ most common - soda-lime and borosilicate glasses familiar as bottles and ovenware.​ hard, brittle, and vulnerable to stress concentrations. Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.4. Classification of Materials 1880 1.4.2. Ceramics Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.4. Classification of Materials 1.4.3. Polymers Two industrially important polymeric materials are plastics and elastomers​ Plastics – synthetic materials which are processed by forming or molding into shape.​ Elastomers – can be elastically deformed and can return to their original shape​ Properties: less dense, corrosion resistant, resistant to electrical current Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.4. Classification of Materials 1.4.3.1. Polymers-plastics Plastics – synthetic materials which are processed by forming or molding into shape.​ Thermoplastic – melt on heating and may be processed by a variety of molding and extrusion techniques (polyethylene PE, polypropylene, polystyrene PS, and polyvinyl chloride PVC) Thermosetting plastics – polymers cannot be melted or remelted (alkyds, amino and phenolic resins, epoxies, polyurethanes, and unsaturated polyesters) Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.4. Classification of Materials 1.4.3.2. Polymers-elastomers Elastomers – can be elastically deformed and can return to their original shape​ Properties: less dense, corrosion resistant, resistant to electrical current Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.4. Classification of Materials 1.4.4 Composites/hybrids Combinations of two or more materials in a predetermined configuration and ​ scale. ​ Combine the attractive properties of the other families of materials while avoiding some of their drawbacks.​ Includes fiber and particulate composites, sandwich structures, lattice structures, foams, SEM of synthetic cables, and laminates; almost all the materials rubber tire with sppherical of nature—wood, bone, skin, and leaf—are carbon particles hybrids. ​ Fiber-reinforced composites are the most familiar. Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.4. Classification of Materials 1.4.4 Composites/hybrids Branches of Composites Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.4. Advanced Materials Materials that are utilized in high-technology applications Include semiconductors, biomaterials, smart materials, nano materials Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.5. Advanced Materials Semiconductors Have electrical properties that are intermediate between the electrical conductors and insulators. The electrical characteristics of these materials are extremely sensitive to the presence of minute concentrations of impurity atoms. Semiconductors have made possible the advent of integrated circuitry that has totally revolutionized the electronics and computer industries. Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.5. Advanced Materials Biomaterials Employed in components implanted into the human body for replacement of diseased or damaged body parts. These materials must not produce toxic substances and must be compatible with body tissues. Metals, ceramics, polymers, composites, etc. may be used as biomaterials. Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.5. Advanced Materials (bioceramics) High Strength (non-porous) Bioceramics High bioactivity (porous) Bioceramics Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.5. Advanced Materials Smart Materials PV cells new and state-of-the-art materials adjective “smart” implies that these materials are able to sense changes in their environments and then respond to these changes in predetermined manners Example - piezoelectric sensors in helicopters to reduce aerodynamic cockpit noise that is created by the rotating rotor blades Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.5. Advanced Materials Carbon nanotubes (CNT) Nano Materials It is now possible to manipulate and move atoms and molecules to form new structures and, thus, design new materials that are built from simple atomic-level constituents This ability to carefully arrange atoms provides opportunities to develop mechanical, electrical, magnetic, and other properties that are not otherwise possible. The study of the properties of these materials is termed “nanotechnology” Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.6. Modern Material Needs 1. Sophisticated material that are sensitive to the environment and climate change. 2. Nuclear revolution need materials to avoid radiation exposure. Nuclear power produces infinitely large amount of energy 3. Transportation needs materials for weight reduction and increase efficiency. 4. Solar technology needs cheaper and efficient material to harvest solar energy. 5. Metal extraction method needs material to reduce the amount of energy used. 6. Materials for space exploration. Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.7. Chemical composition of Engineering Materials 1.7.1 Atomic bonding refers to the forces that hold atoms together in molecules and solids. properties such as melting point, boiling point, thermal conductivity and electrical conductivity of materials are governed by atomic bonding of materials Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.7. Chemical composition of Engineering Materials 1.7.1 Atomic bonding Ionic Bonding Formed when one has a small number of electrons in the valence shell (metal) and one has an almost full outer shell (non-metal). Ionic bonds are strong and stiff. As a result, they generally give a material with high strength, high elastic modulus, high melting point, and poor electrical conductivity. Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.7. Chemical composition of Engineering Materials 1.7.1 Atomic bonding Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.7. Chemical composition of Engineering Materials 1.7.1 Atomic bonding Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.7. Chemical composition of Engineering Materials 1.7.1 Atomic bonding Metallic Bonding occurs when electrons are “surrendered” to a common pool and become shared by all the atoms in the solid metal generally results in a material being strong and stiff and gives high elastic modulus, high strength, good electrical conductivity, metallic luster, and high ductility Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.7. Chemical composition of Engineering Materials 1.7.1 Atomic bonding Covalent Bonding two atoms that are covalently bonded will share at least one electron from each atom generally produces materials that can be very stiff and with very high elastic modulus, high strength, high melting point, and low electrical conductivity. dominant bonding found in silicate ceramics and glasses. It also occurs in the backbone of polymer chains and in the cross-links in thermosetting polymers. Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.7. Chemical composition of Engineering Materials 1.7.1 Atomic bonding Examples of materials in covalent bonding : carbon allotropes Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.7. Chemical composition of Engineering Materials 1.7.2 Chemical Composition of Some Notable Materials: Metals Unified Numbering System (UNS) by ASTM Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.7. Chemical composition of Engineering Materials 1.7.2 Chemical Composition of Some Notable Materials: Metals Unified Numbering System (UNS) by ASTM Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  1.7. Chemical composition of Engineering Materials 1.7.2 Chemical Composition of Some Notable Materials: Polymers Note: These Material codes are from NTN only and are not globally used Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  Seatwork no. 1 1-4 Components of the Discipline in MS&E 5-10 Give a specific example of interrelationship of these disciplines (e.g. Properties Processing : Quenching of steel would lose some of its ductility in return for gaining of some brittleness) 11-14 (4) Major Classification of Materials 15-18 (4) Advance Materials 19-20 Choose two (2) properties of materials and define Engr. Marlowe Jay V. Dignos, M.S ME361 – Materials Science and Engineering  Module 2 Crystal Structure of Materials and The Unit Cell Engr. Marlowe Jay V. Dignos, M.S  ME361 Module 2 2.1. Fundamental Concepts and Importance 2.2. The Unit Cell 2.3. Lattice Parameters and the 7 Crystal Systems 2.4. Metallic Crystal Structures 2.5. Theoretical Density Engr. Marlowe Jay V. Dignos, M.S  2.1. Fundamental Concepts and Importance Engr. Marlowe Jay V. Dignos, M.S  2.1. Fundamental Concepts Why Study? Diamond Graphite Carbon atoms arranged Carbon atoms arranged in in FCC (3D) hexagonal sheets (2D) Engr. Marlowe Jay V. Dignos, M.S  2.2. The Unit Cell Use to define crystal structure Unit structure that describes the totality of a crystal Quartz (𝑆𝑖𝑂2) Table salt (NaCl) Crystal System: Hexagonal Crystal System: Cubic (FCC) Lattice parameters: Lattice parameters: a = 4.9133 Å a = 5.6402 Å c = 5.4053 Å Engr. Marlowe Jay V. Dignos, M.S  2.3. Lattice Parameters and the 7 Crystal Systems Consider these 2 for study Engr. Marlowe Jay V. Dignos, M.S  2.3. Lattice Parameters and the 7 Crystal Systems Engr. Marlowe Jay V. Dignos, M.S  2.4. Metallic Crystal Structures 2.4.1. Cubic Simple/Primitive Body centered (BCC) Face centered (FCC) Reduced-Sphere Model Hard-Sphere Model Engr. Marlowe Jay V. Dignos, M.S  2.4. Metallic Crystal Structures 2.4.2. Hexagonal Closed Pack (HCP) Engr. Marlowe Jay V. Dignos, M.S  2.4. Metallic Crystal Structures 2.4.3. Number of atoms in a unit cell, N 𝑁𝑓 𝑁𝑐 𝑁𝑐𝑢𝑏𝑖𝑐 = 𝑁𝑖 + + 2 8 𝑁𝑖 = number of interior atoms 𝑁𝑓 = 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑓𝑎𝑐𝑒 𝑎𝑡𝑜𝑚𝑠 𝑁𝑐 = 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑐𝑜𝑟𝑛𝑒𝑟 𝑎𝑡𝑜𝑚𝑠 Engr. Marlowe Jay V. Dignos, M.S  2.4. Metallic Crystal Structures 2.4.3. Number of atoms in a unit cell, N 𝑁𝑓 𝑁𝑐 𝑁𝑓 𝑁𝑐 𝑁𝑓 𝑁𝑐 𝑁 = 𝑁𝑖 + + 𝑁 = 𝑁𝑖 + + 𝑁 = 𝑁𝑖 + + 2 8 2 8 2 8 0 8 0 8 6 8 𝑁 =0+ + 𝑁 =1+ + 𝑁 =0+ + 2 8 2 8 2 8 𝑁 = 1 𝑎𝑡𝑜𝑚 𝑁 = 2 𝑎𝑡𝑜𝑚𝑠 𝑁 = 4 𝑎𝑡𝑜𝑚𝑠 Engr. Marlowe Jay V. Dignos, M.S  2.4. Metallic Crystal Structures 2.4.3. Number of atoms in a unit cell, N 𝑁𝑓 𝑁𝑐 𝑁𝐻𝐶𝑃 = 𝑁𝑖 + + 2 6 2 12 𝑁𝐻𝐶𝑃 =3+ + 2 6 𝑁𝐻𝐶𝑃 = 6 𝑎𝑡𝑜𝑚𝑠 Engr. Marlowe Jay V. Dignos, M.S  2.4. Metallic Crystal Structures 2.4.3. Atomic Packing Factor, APF A parameter used to describe how atoms are arranged in a unit cell Ratio of atom spheres to the total unit cell volume 𝑉𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑎𝑡𝑜𝑚𝑠 𝑖𝑛 𝑎 𝑢𝑛𝑖𝑡 𝑐𝑒𝑙𝑙 𝐴𝑃𝐹 = 𝑡𝑜𝑡𝑎𝑙 𝑢𝑛𝑖𝑡 𝑐𝑒𝑙𝑙 𝑣𝑜𝑙𝑢𝑚𝑒 𝑉𝑠 𝐴𝑃𝐹 = 𝑉𝑐 Engr. Marlowe Jay V. Dignos, M.S  2.4. Metallic Crystal Structures 2.4.3. Atomic Packing Factor, APF Example: Compute the APF of FCC 𝑉𝑠 𝐴𝑃𝐹 = 𝑉𝑐 𝐴𝑃𝐹 = 0.74 Engr. Marlowe Jay V. Dignos, M.S  2.4. Metallic Crystal Structures 2.4.3. Atomic Packing Factor, APF Seatwork: Compute the APF of BCC, Simple Cubic, and HCP Engr. Marlowe Jay V. Dignos, M.S  2.4. Metallic Crystal Structures 2.4.3. Atomic Packing Factor, APF Seatwork: Compute the APF of BCC, Simple Cubic, and HCP 𝐴𝑃𝐹𝐵𝐶𝐶 = 0.68 𝐴𝑃𝐹𝑆𝐶 = 0.52 𝐴𝑃𝐹𝑆𝐶 = 0.74 Engr. Marlowe Jay V. Dignos, M.S  2.5. Theoretical Density Maximum density that a crystal can achieve 𝑛𝐴 𝜌= 𝑉𝑐 𝑁𝐴 Engr. Marlowe Jay V. Dignos, M.S  2.5. Theoretical Density Example: Copper has an atomic radius of 0.128 nm, an FCC crystal structure, and an atomic weight of 63.5 g/mol. Compute its theoretical density, and compare the answer with its measured density 𝑛𝐴𝐶𝑢 𝜌𝐶𝑢 = 𝜌𝐶𝑢 = 8.89g/𝑐𝑚3 𝑉𝑐 𝑁𝐴 𝑛𝐴𝐶𝑢 𝜌𝐶𝑢 = (16𝑅 3 2)𝑁𝐴 4𝑎𝑡𝑜𝑚𝑠 63.5𝑔 ( )( ) 𝜌𝐶𝑢 = 𝑢𝑛𝑖𝑡𝑐𝑒𝑙𝑙 𝑚𝑜𝑙 16 1.28𝑥10−8 𝑐𝑚 3 2 6.022𝑥1023 𝑎𝑡𝑜𝑚𝑠 𝑢𝑛𝑖𝑡𝑐𝑒𝑙𝑙 𝑚𝑜𝑙 Engr. Marlowe Jay V. Dignos, M.S  Module 3 Material Properties and Characteristics Engr. Marlowe Jay V. Dignos, M.S  ME361 Module 3 3.1 Material Information for Design 3.2 General Properties 3.3 Mechanical Properties 3.4 Thermal Properties 3.5 Electrical Properties 3.6 Optical Properties 3.7 Eco-properties Engr. Marlowe Jay V. Dignos, M.S  3.1 Material Information for Design ABS (Acrylonitrile-butadiene-styrene) Engr. Marlowe Jay V. Dignos, M.S  3.1 Material Information for Design ABS (Acrylonitrile-butadiene-styrene) Engr. Marlowe Jay V. Dignos, M.S  3.1 Material Information for Design Where it came from? Engr. Marlowe Jay V. Dignos, M.S  3.1 Material Information for Design Engr. Marlowe Jay V. Dignos, M.S  3.1 Material Information for Design Application? Material Property Requirement? Engr. Marlowe Jay V. Dignos, M.S  3.1 Material Information for Design Application? Material Property Requirement? Engr. Marlowe Jay V. Dignos, M.S  3.1 Material Information for Design Application? Material Property Requirement? Engr. Marlowe Jay V. Dignos, M.S  3.2 General Properties Engr. Marlowe Jay V. Dignos, M.S  3.2 General Properties The density, ρ (units: kg/m3 ) - mass per unit volume The price (units: $/kg) 11 Engr. Marlowe Jay V. Dignos, M.S  3.2 General Properties 12 Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties 13 Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties Engg’Stress-Strain Curve 15 Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Elastic Modulus, E (Mpa/GPa) the measure of an object's or substance's resistance to being deformed elastically when stress is applied the slope of the initial, linear- elastic, part of the stress-strain curve. Young’s modulus, 𝐄 – “tensile or compressive loading” 16 Shear modulus, 𝐆, - “shear loading” 16 Bulk modulus, 𝐊 – “hydrostatic 𝒔𝒕𝒓𝒆𝒔𝒔 𝝈 pressure” 𝑬= = 𝒔𝒕𝒓𝒂𝒊𝒏 𝜺 Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Elastic Modulus, E (Mpa/GPa) Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Poisson’s ratio, 𝝂 -Defined as the ratio of the lateral and axial strains 𝜺 𝒙 𝜺𝒚 𝝂= = 𝜺𝒛 𝜺𝒛 𝒍 − 𝒍𝑶 𝜺𝒛 = 𝒍𝑶 𝒘 − 𝒘𝑶 𝜺𝒙 = 𝒘𝑶 Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Elastic Modulus, E (MPa/GPa) Young’s modulus, 𝐄 “tensile or compressive loading” 3G E= G 1 + 3K Shear modulus, 𝐆 “shear loading” E G= 2(1 + ν) Bulk modulus, 𝐊 “hydrostatic pressure” 19 E K= 3(1 − 2ν) ν = 𝑃𝑜𝑖𝑠𝑠𝑜𝑛′ 𝑠 𝑅𝑎𝑡𝑖𝑜 Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Elastic Modulus, E (Mpa/GPa) Estimating Moduli Young’s modulus 𝐄 for copper is 124 GPa; its Poisson’s ratio 𝛎 is 0.345. What is its shear modulus, 𝐆? Inserting the values for 𝐄 and 𝛎 in the equation: 124 GPa G= = 46.1 GPa 2(1 + 0.345) 20 The measured value is 45.6 GPa, a difference of only 1%. Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Yield Strength, 𝛔𝒚 (Mpa/GPa) the maximum stress that can be applied before a material begins to change shape permanently For metals: the stress at which the stress-strain curve for axial loading deviates by a strain of 0.2% from the linear-elastic line. It is the same in tension and compression For polymers: the stress at which the stress-strain curve becomes markedly nonlinear, at a strain typically of 1% 21 For ceramics: Fracture strength in tension while crushing strength in compression Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Yield Strength, 𝛔𝒚 (Mpa/GPa) 22 Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Flexural Strength, 𝛔𝒇𝒍𝒆𝒙 (Mpa/GPa) Also called Modulus of Rupture (MOR) the maximum surface stress in a bent beam at the instant of failure. 23 Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Ultimate Strength, 𝛔𝒖 (Mpa/GPa) the ability of a material to resist a force that tends to pull it apart for brittle solids — ceramics, glasses, and brittle polymers — it is the same as the failure strength in tension 24 Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Endurance limit, 𝛔𝒆 (Mpa/GPa) Also called Fatigue the stress below which a material can endure an infinite number of repeated load cycles without exhibiting failure. 25 Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Hardness, 𝑯 (Mpa/GPa) the resistance of a specific material to localized plastic deformation or indentation the resistance of the material to scratching, abrasion or cutting measured by pressing a pointed diamond or hardened steel ball into the material’s 26 surface. Related to yield strength by 𝑯 ≈ 𝟑𝝈𝒚 Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Hardness, 𝑯 (Mpa/GPa) Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Fracture Toughness, 𝑲𝒄 𝑴𝑷𝒂 𝒎 or 𝒎𝑱𝟐 measure the resistance of a material to the propagation of a crack Engr. Marlowe Jay V. Dignos, M.S  𝑱 3.3 Mechanical Properties: Fracture Toughness, 𝑲𝒄 𝑴𝑷𝒂 𝒎 or 𝒎𝟐 Fracture Toughness Empirical Formula from HV data Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Characteristic Terminologies Strength - property which opposes the deformation or breakdown of material in presence of external forces or load Elasticity - ability to resist a deformation/elongation and to return to its original size and shape when force is removed Plasticity - ability to undergo permanent deformation, a non- reversible change of shape in response to applied forces Ductility - degree to which a material can sustain plastic deformation under tensile stress before failure; material's amenability to drawing. 31 Malleability - ability to be formed in the form of a thin sheet by hammering or rolling Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Characteristic Terminologies Brittleness - when subjected to stress, it fractures with little elastic deformation and without significant plastic deformation Stiffness - extent to which an object resists deformation in response to an applied force, often measured by the Young's Modulus Hardness - a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion Creep - tendency to move slowly and deform permanently under the influence of external mechanical stress (i.e. elevated temperature) Fatigue - weakening of material caused by the repeated loading of the material Engr. Marlowe Jay V. Dignos, M.S  3.3 Mechanical Properties: Characteristic Terminologies Resilience - ability to absorb the maximum energy when it is deformed elastically by applying stress and release the energy when stress is removed Toughness - the ability to withstand shock loading without fracture, measures the energy required to crack a material Weldability - ability to be welded and retain its properties after the welding Formability - capability to undergo plastic deformation to a given shape without defects Castability - represents how easy it is to pour molten material into a mold and obtain a defect-free casting Engr. Marlowe Jay V. Dignos, M.S  3.4 Thermal Properties 34 Engr. Marlowe Jay V. Dignos, M.S  3.4 Thermal Properties: Glass Temperature 𝑻𝒈 (𝑲 𝒐𝒓 °𝑪) an important feature of polymer behavior it marks a region of dramatic changes in the physical and mechanical properties < 𝑻𝒈 : due to lack of mobility, the polymers are hard and brittle like glass 35 > 𝑻𝒈 : due to some mobility, the polymers are soft and flexible like rubber Engr. Marlowe Jay V. Dignos, M.S  3.4 Thermal Properties: Melting Temperature 𝑻𝒎 (𝑲 𝒐𝒓 °𝑪) temperature at which the solid and liquid forms of a pure substance can exist in equilibrium as heat is applied to a solid, its temperature will increase until the melting point is reached, more heat then will convert the solid into a liquid Engr. Marlowe Jay V. Dignos, M.S  3.4 Thermal Properties: Max Service Temp, 𝑻𝒎𝒂𝒙 (𝑲 𝒐𝒓 °𝑪) Min Service Temp, 𝑻𝒎𝒊𝒏 (𝑲 𝒐𝒓 °𝑪) 𝑻𝒎𝒂𝒙 : highest temperature at which the material can reasonably be used without oxidation, chemical change, or excessive creep becoming a problem. 𝑻𝒎𝒊𝒏 : the temperature below which the material becomes 37 brittle or otherwise unsafe to use. Engr. Marlowe Jay V. Dignos, M.S  3.4 Thermal Properties: Specific Heat, 𝒄𝒑 𝑱 𝒌𝒈−𝑲 the quantity of heat required to raise the temperature of one gram of a substance by 𝟏°𝑪 measurement is usually made at constant (atmospheric) pressure so it is given the symbol (𝒄𝒑) for gases, it is more usual to measure the heat capacity at constant volume (𝒄𝒗), and for gases this differs from Cp Engr. Marlowe Jay V. Dignos, M.S  3.4 Thermal Properties: Thermal Shock Resistance, ∆𝑻𝒔 , 𝐾 𝑜𝑟 °𝐶 the maximum temperature difference through which a material can be quenched suddenly without damage temperature fluctuations cause thermal stresses in the ceramic, and consequently the propagation of micro-cracks that permanently damage the 39 material. Engr. Marlowe Jay V. Dignos, M.S  3.4 Thermal Properties: Linear Thermal Expansion Coefficient , 𝜶, 𝑲−𝟏 𝑜𝑟 °𝐶 −1 thermal strain per degree of temperature change ∆𝑳 is the change in length due to heating or to cooling 𝑳𝒐 is the original length of specimen at room temperature ∆𝑻 is the temperature change in °C, during the test Engr. Marlowe Jay V. Dignos, M.S  3.5 Electrical Properties 41 Engr. Marlowe Jay V. Dignos, M.S  3.5 Electrical Properties: Electrical Resistivity, 𝝆𝒆 , Ω − 𝑚 property of a material that measures how strongly it resists electric current more than 10−8 Ω − m for good conductors more than 1016 Ω − m for best insulators 42 Engr. Marlowe Jay V. Dignos, M.S  3.5 Electrical Properties: Electrical Conductivity, 𝜿𝒆 , S m or Ω𝑚 −1 the measure of the capability of the material to pass the flow of electric current. differs from one material to another depending on the ability to let the electricity flow through them 43 Engr. Marlowe Jay V. Dignos, M.S  3.5 Electrical Properties: Dielectric Constant, 𝜺𝒓 Measures the tendency of an insulator to be polarized when placed in an electric field. For gases: 𝜺𝒓 = 𝟏 For insulators: 𝟐< 𝜺𝒓 < 𝟑𝟎 44 Engr. Marlowe Jay V. Dignos, M.S  3.5 Electrical Properties: Dielectric Constant, 𝜺𝒓 Measures the tendency of an insulator to be polarized when placed in an electric field. For gases: 𝜺𝒓 = 𝟏 For insulators: 𝟐< 𝜺𝒓 < 𝟑𝟎 45 Engr. Marlowe Jay V. Dignos, M.S  3.6 Optical Properties These properties are directly related to the refractive index and the extinction index of the medium Among the optical properties, refraction, absorption, reflection, and scattering of light are the most important Engr. Marlowe Jay V. Dignos, M.S  3.7 Eco - Properties 47 Engr. Marlowe Jay V. Dignos, M.S  3.7 Eco - Properties MJ Embodied energy kg is the energy required to extract 1 kg of a material from its ores and feedstock kg CO2 footprint kg is the mass of carbon dioxide released into the atmosphere during the production of 1 kg of material Engr. Marlowe Jay V. Dignos, M.S  SEATWORK: Case Study Instructions: 1. Choose a material in specific application 2. Identify its material category: metal, polymer, ceramics, composites 3. Describe and elaborate the working conditions (in-service application) or application associated 4. Material properties that are significantly considered with respect to its application. 5. State your references e.g. I. Material in specific application: Gear train in a power transmission II. Material Category: Metal III. In Service Condition: Gear train in a power transmission is a famous mechanism and is widely used in automobile application. Gear train is a mechanism which involves series of gear with different gear ratios. These gears are used in power transmission from the internal combustion engine to the wheels of an automobile. (Elaborate more) IV. Material Properties: In order for the gear train to work, the material that should be used should be capable of handling the power transmission requirement. The gears should be hardened with no allowable deformation to occur to prevent jamming which interlocks along their contact. (elaborate) Engr. Marlowe Jay V. Dignos, M.S  Module 4 Materials Testing Engr. Marlowe Jay V. Dignos, M.S  ME361 Module 4 4.1 Destructive Mechanical Testing 4.2 Tensile Testing 4.3 Compression Testing 4.4 Hardness Testing 4.5 Toughness Testing 4.6 Shear Testing 4.7 Bending Test Engr. Marlowe Jay V. Dignos, M.S  Why materials are tested? ✓ Ensure quality ✓ Test properties ✓ Prevent failure in use ✓ Make informed choices in using materials Factor of Safety is the ratio comparing the actual stress on a material and the safe useable stress. Engr. Marlowe Jay V. Dignos, M.S  Why materials are tested? OceanGate’s Titan What could have caused the implosion of the vessel? Engr. Marlowe Jay V. Dignos, M.S  Major Forms of Testing ✓ Destructive Mechanical tests requires destroying the specimen in order to measure the property requires a specially prepared specimen ✓ Non-destructive tests (NDT) measures attributes of the specimen without damaging it does not normally need a prepared specimen 5 typically used to find flaws inside a part Engr. Marlowe Jay V. Dignos, M.S  4.1 Destructive Mechanical Testing Mechanical testing is used to find the mechanical properties of a material as it performs in a particular environment Some mechanical tests provide information on several properties at once: Tensile test - ultimate tensile strength, yield strength, modulus of elasticity, and even how ductile or brittle it is, based on the stress- strain curve and the manner in which the material fractures Mechanical testing is an important part of design or manufacturing processes, and testing services can be conducted in-house or carried out by external testing laboratories Engr. Marlowe Jay V. Dignos, M.S  4.1 Destructive Mechanical Testing Regardless of where they are conducted, the primary purpose of mechanical testing is to ensure the safety of any final products or structures. Environmental conditions are important, so tests should be performed under similar conditions to those faced by the final product. Mechanical tests can also be used to mitigate unexpected failures and as part of a failure investigation Engr. Marlowe Jay V. Dignos, M.S  4.1 Destructive Mechanical Testing Mechanical Property Test Strength Tensile/Compression/Shear Hardness Rockwell/Brinell/Vickers Toughness Impact: Charpy/Izod Engr. Marlowe Jay V. Dignos, M.S  4.2 Tensile Testing Engr. Marlowe Jay V. Dignos, M.S  4.2 Tensile Testing Strength – property which opposes the deformation of material in presence of external forces or load This test is directly related to the safety of the products. The test is essential to perform to measure the quality or 10 strength of the materials under extreme tension forces during usage. Engr. Marlowe Jay V. Dignos, M.S  4.2 Tensile Testing A Universal Testing Machine (UTM), also known as a tensile testing machine/tester, is an electromechanical testing system that applies a force to raw materials or components to test for both tensile and compressive strength Engr. Marlowe Jay V. Dignos, M.S  4.2 Tensile Testing Engr. Marlowe Jay V. Dignos, M.S  4.2 Tensile Testing 13 Engr. Marlowe Jay V. Dignos, M.S  4.2 Tensile Testing 14 Stress-Strain Curves for Different Materials Engr. Marlowe Jay V. Dignos, M.S  4.2 Tensile Testing Engr. Marlowe Jay V. Dignos, M.S  4.3 Compression Testing Engr. Marlowe Jay V. Dignos, M.S  4.3 Compression Testing During a typical compression test, data are collected regarding the applied load, resultant deformation or deflection, and condition of the 17 specimen. 17 Engr. Marlowe Jay V. Dignos, M.S  4.3 Compression Testing Metals and plastics, for example, are more efficient at resisting tensile loads. Therefore, they are more commonly tested using tensile loading, depending on the application, of course. Materials, such as concrete, brick, and some ceramic products, are more often used in applications for their compressive loading properties and are, therefore, tested in compression. Engr. Marlowe Jay V. Dignos, M.S  4.3 Compression Testing Engr. Marlowe Jay V. Dignos, M.S  4.3 Compression Testing Engr. Marlowe Jay V. Dignos, M.S  4.3 Compression Testing Failure Patterns when L/D > 5,Buckling when L/D > 2.5, Shearing when L/D > 2.0 and friction is present at the contact surfaces, Double barrelling when L/D < 2.0 and friction is present at the contact surfaces, Barrelling 21 Engr. Marlowe Jay V. Dignos, M.S  4.4 Hardness Testing Hardness is the ability to withstand indentation, scratches, or abrasion Engr. Marlowe Jay V. Dignos, M.S  4.4 Hardness Testing 4.4.1 Mohs Hardness (Scratch Test) 23 Engr. Marlowe Jay V. Dignos, M.S  4.4 Hardness Testing 4.4.2 Brinell Hardness Test Principle: The Brinell hardness test involves pressing a hard spherical indenter (usually made of tungsten carbide) into the surface of a material using a specified load. The diameter of the indentation left on the material's surface is measured. Indentation Size: The indentation size is relatively large, making it suitable for testing softer materials or materials with coarse grain structures. Application: Commonly used for testing materials such as castings, forgings, and softer metals Symbol: Represented as HB (e.g., HB 300) Advantages: Provides a quick and easy way to assess hardness Engr. Marlowe Jay V. Dignos, M.S  4.4 Hardness Testing 4.4.3 Vickers Hardness Test Principle: The Vickers hardness test uses a square-based pyramidal diamond indenter to create an indentation. The diagonal lengths of the square indentation are measured. Indentation Size: The Vickers test produces smaller indentations compared to Brinell, making it suitable for a wide range of materials, including both metals and ceramics. Application: Widely used for testing materials with varying hardness levels, including metals, ceramics, and composites. Symbol: Represented as HV (e.g., HV 200). 25 Advantages: Can be used for materials of varying hardness levels due to its relatively small indentation size. It's also suitable for thin materials. Engr. Marlowe Jay V. Dignos, M.S  4.4 Hardness Testing 4.4.4 Rockwell Hardness Test Principle: The Rockwell hardness test measures hardness by applying a preliminary minor load and then a major load using various indenters (e.g., steel ball, diamond cone). The depth of penetration (rebound) is measured, and hardness values are determined based on the difference between the two depth measurements. Indentation Size: Rockwell hardness tests produce smaller indentations compared to Brinell but larger than Vickers, making it suitable for a wide range of materials. Application: Used for a variety of materials, including metals, plastics, and some ceramics. Symbol: HRC (Rockwell C hardness) and HRB (Rockwell B hardness) Advantages: Provides a convenient way to measure the hardness of materials and is widely used in industry due to its speed and ease of use. Engr. Marlowe Jay V. Dignos, M.S  4.4 Hardness Testing Engr. Marlowe Jay V. Dignos, M.S  4.4 Hardness Testing Engr. Marlowe Jay V. Dignos, M.S  4.5 Toughness Testing Engr. Marlowe Jay V. Dignos, M.S  4.5 Toughness Testing Toughness is the ability of metals to withstand impact Using the impact test, the energy needed to break the material can be measured easily and can be used to measure the toughness of 30 the material and the yield strength. Engr. Marlowe Jay V. Dignos, M.S  4.5 Toughness Testing 4.5.1 Izod Test Test Setup: In the Izod test, a specimen (usually a notched rectangular bar) is clamped vertically as a pendulum swings down and strikes the specimen on its notched side. The specimen is positioned vertically, and the impact occurs in a horizontal plane. Specimen Geometry: The Izod test typically uses a notched specimen with a V-notch or U-notch on one side. The notch introduces a stress concentration, making it a sensitive indicator of material toughness. Energy Measurement: In the Izod test, the energy required to break the specimen is measured in joules. The pendulum's initial height and the angle of swing are used to calculate the energy absorbed during the impact. Applications: The Izod test is often used for assessing the impact resistance of plastics and polymers, as well as some metals. It is particularly suitable for materials with higher toughness. Engr. Marlowe Jay V. Dignos, M.S  4.5 Toughness Testing 4.5.2 Charpy Test Test Setup: In the Charpy test, the specimen (typically a notched or unnotched V-shaped bar) is clamped horizontally, and the pendulum strikes the specimen on its unnotched side. The impact occurs in a vertical plane, causing the specimen to break. Specimen Geometry: The Charpy test can use both notched and unnotched specimens, but it is often associated with notched specimens. The notch geometry may vary, including V-notch, U-notch, or keyhole notch. Energy Measurement: In the Charpy test, the energy absorbed by the specimen during impact is also measured in joules. However, the calculation is based on the 32 difference in the pendulum's potential energy before and after the impact. Applications: The Charpy test is widely used in the testing of metals, especially in the construction, automotive, and manufacturing industries. It is less commonly used for polymers. Engr. Marlowe Jay V. Dignos, M.S  4.5 Toughness Testing 33 Engr. Marlowe Jay V. Dignos, M.S  4.5 Toughness Testing 34 Engr. Marlowe Jay V. Dignos, M.S  4.6 Shear Testing 35 Engr. Marlowe Jay V. Dignos, M.S  4.6 Shear Testing Shear Strength –ability to resist forces that cause the material's internal structure to slide against itself Purpose: Shear testing is performed to determine a material's shear strength, which is crucial in various engineering and construction applications. It helps assess a material's ability to withstand shearing forces and deformation, providing insights into its structural integrity and suitability for specific uses Test Setup: In a typical shear test, a specimen is prepared with a specified geometry, including a defined cross-sectional area and height. The specimen is securely held in a testing machine. A shear force is applied in a direction36 parallel to the designated shear plane. This force may be applied at a constant rate until the material fails, or it may be applied incrementally to measure shear strength at different levels of deformation. Engr. Marlowe Jay V. Dignos, M.S  4.6 Shear Testing Types of Shear Tests: There are several variations of shear tests, including: Direct Shear Test: In this test, a sample is subjected to a direct shear force along a horizontal plane within the material. It's commonly used for testing soil and rock materials in geotechnical engineering. Single Shear Test: This test evaluates the shear strength of materials like adhesives or composites by applying a shearing force to a single specimen. 37 Double Shear Test: In this test, two specimens are used, and the shearing force is applied between them. It's often used for testing the shear strength of bolts, rivets, and fasteners. Engr. Marlowe Jay V. Dignos, M.S  4.6 Shear Testing Applications: Shear testing is applied in various industries, including civil 38 engineering (e.g., assessing soil stability), materials science (e.g., evaluating the strength of adhesives or composites), and manufacturing (e.g., testing welds or fasteners). It's crucial in designing structures and materials to ensure they can withstand shear forces without failing. Engr. Marlowe Jay V. Dignos, M.S  4.6 Shear Testing 39 Engr. Marlowe Jay V. Dignos, M.S  4.6 Shear Testing: Torsion In addition to tension and compression, a work-piece may be subjected to shear strains Torsion test used for determination of properties in “shear.” Usually performed on a thin tubular specimen The ratio of the shear stress to the shear strain in the elastic range is known as the shear modulus or modulus of rigidity The angle of twist to fracture in the torsion of solid round bars and elevated temp can help estimate forge-ability of metals. 40 Engr. Marlowe Jay V. Dignos, M.S  4.6 Shear Testing: Torsion 41 Engr. Marlowe Jay V. Dignos, M.S  4.7 Bending Test 42 Engr. Marlowe Jay V. Dignos, M.S  4.7 Bending Test Flexural Strength – stress at failure in bending Purpose: The primary purpose of a bending test is to determine how a material responds to applied bending forces. It is used to assess the material's ability to withstand bending without breaking or undergoing excessive deformation. Test Setup: In a typical bending test, a rectangular or cylindrical specimen is supported at two points (a span) and subjected to a load applied perpendicular to 43 the span. The material is bent, causing it to experience tensile and compressive stresses on opposite sides of the neutral axis. The test may be performed in various 43 configurations, such as three-point bending or four-point bending, depending on the specific requirements. Engr. Marlowe Jay V. Dignos, M.S  4.7 Bending Test Measurement of Properties: Flexural Strength: This is the maximum stress experienced by the material during bending. It indicates the material's resistance to bending loads before failure. Flexural Modulus: Also known as the modulus of elasticity in bending, it measures a material's stiffness. It quantifies how much a material deforms under a given bending load. Deflection: Bending tests also measure the amount of deflection or deformation that occurs as the material is bent. This information is crucial for understanding how a material behaves under different loads. Engr. Marlowe Jay V. Dignos, M.S  4.7 Bending Test Applications: In civil engineering, they assess the strength of construction materials like concrete and steel beams. In materials science, they evaluate the mechanical properties of composites, polymers, and metals. In manufacturing, they ensure the quality of components subjected to bending loads, such as beams, pipes, and rods. Engr. Marlowe Jay V. Dignos, M.S  4.7 Bending Test Engr. Marlowe Jay V. Dignos, M.S