In the following module we will focus on brittle fracture of ceramic materials. iPad ICE Publishing is part of the Institution of Civil Engineers. Thanks, By: In order to view it, please Electrical Properties IV. Spring loaded needle with a diameter of 1 mm 10% decrease in Barcol hardness of a resin composite results in a 20% decrease in the flexural strength.Shore hardness test: Shore hardness test Measure the hardness of rubbers & soft plastics Values  0 to 100PowerPoint Presentation: Material Compressive Strength ( MPa ) Tensile strength ( MPa ) Modulus of Elasticity ( GPa ) Hardness Cast metal 1140 177 – 202 335 DFG 46 – 50 55 – 69 Amalgam 396 – 423 48 – 64 52 – 58 120 GIC 150 6.6 9 48 Composite 280 – 385 40 – 54 16 – 21 43 – 70 Ceramics 150 24 – 37 70 - 107 591 Enamel 384 10.3 84 - 130 355 – 431 Dentin 297 105.5 14.7 339 – 418Conclusion: Conclusion Single property  Combined propertiesReferences: References Phillip’s science of dental materials 11 th edition. The chemical and biologic properties of dental materials are discussed with each group of materials presented in the chapters that follow. Correct proportion important. Fracture occurs along the vertical plane. Mechanical properties are subset of physical properties that are based on the laws of mechanics that is the physical science that deals with energy and forces and their effects on the bodies. The indentation produced on the surface of a material from an applied force of a sharp point or an abrasive particle results from the interaction of numerous properties.PowerPoint Presentation: SURFACE HARDNESS TESTSBrinell hardness test: Brinell hardness test Small, hardened steel ball Indentation – round Diameter of the dentRockwell hardness test: Rockwell hardness test Ball or metal cone indenter Depth of the indentation is measuredPowerPoint Presentation: Advantages : Disadvantages :Vickers Hardness Test: Vickers Hardness Test Pyramid shaped diamond with a square base Diagonals of the square-shaped indentationPowerPoint Presentation: Significant advantage: Testing very small specimens Used on materials that are soft as well as hard. As this property is related to the attraction forces within the material, it is usually same, when the material is in tension or compression. a) Acrylic resin 1.2 gm/cm³ Density • The amount of mass of a material in a given volume. In metallurgy & in most other disciplines the concept of hardness that is most generally, accepted is its resistance to indentation . HTTPS (Hypertext Transfer Protocol Secure) is a protocol used by Web servers to transfer and display Web content securely. Stronger the basic attraction forces - greater the elastic modulus & the more rigid/stiff the material. The blow is delivered at a certain distance above the clamped end instead of at the center of the specimen supported at both ends as described for the Charpy - type impact test. Flexibility is bending capacity . Given in units of stress times the square root of crack length. Home > Medical Reference and Training Manuals > > Physical Properties of Amalgam. Physical properties include ; 1-density ; 2-thermal properties ; 3-electrical properties ; 4-optical properties; 3 Density. • Density units are g/cm2. There are many challenges for the physical properties of the ideal dental restorative material. Single-edge notch, three-point loading testPowerPoint Presentation: BRITTLENESS Relative inability of a material to sustain plastic deformation before fracture of a material occurs. 3 3. 7aî þ±¤J"CRõTÌÒdn (87 month(s) ago), Mechanical properties of dental materials: Mechanical properties of dental materials By, Dr.S.H.Karthick , II yr PG, Department of Conservative Dentistry & EndodonticsPowerPoint Presentation: Mechanical properties Stress Strain Mechanical properties based on elastic deformation Stress-strain diagram Modulus of elasticity Poisson's ratio Flexibility ResiliencePowerPoint Presentation: Strength properties Proportional limit Elastic limit Yield strength Diametral tensile strength Flexural strength Fatigue strength Impact strength Toughness Fracture toughness Brittleness Ductility Malleability Hardness Hardness tests ConclusionMECHANICAL PROPERTIES: MECHANICAL PROPERTIES Are defined by the laws of mechanics i.e., the physical science that deals with energy and forces and their effects on bodies. Often materials are subject to forces (loads) when they are used. But for brittle materials - Diametral Compression Test. As we go towards the nanoscale level from the molecular level, the electronic properties of materials get modified due to the quantum size effect. The mechanical properties of materials define the behaviour of materials under the action of external forces called loads.. It is the amount of stress required to produce a predetermined amount of permanent strain usually 0.1% or 0.2% which is called the Percent Offset. Шœ–Áއ=©wáϊ.¯ß2 ùù$¸À‡Úµê¹sön XHTkÌ°­vJ‰jž! +Ø~äÁã#˜ýpÑØû­ãJ¤^„WÐÒdn)kÚïÆ¡\:!>IÒûÕéš2ûd†ØXšB¤J¢dbÒF€¼w§5$äñ•HƤª ¥ÉÜT¦}8Íùé ­è'1™‹]W”Ù+3ÄÆÒ"U*,CsÄCc8´òîz.RYsz¾É˜\C%´4™›Ê­Œ…ß9Кb÷ڝ§\Sæ‘!6–¦©Ò©™ƒ¢(FW>]§1'“W/ÝÓS•HN­ ¥ÉÜTæsÊ0K¹ðG´¹Vòa—nΓkT9ñŒ@Hzg General Properties of Dental Materials All materials have physical properties like color, weight, solubility , thermal conductivity , and others , also mechanical properties like hardness or softness , strength or weakness .There is no material till know has ideal physical or mechanical properties . Types: * Sols and Gels * Emulsions Gels ... – A free PowerPoint PPT presentation (displayed as a Flash slide show) on PowerShow.com - id: 48c870-Nzc1Z These can be defined as the strain that occurs when the material is stretched to its proportional limit Flexibility with respect to impression material is important Flexibility  Elastic recoveryPowerPoint Presentation: Resilience Defined as the amount of energy absorbed within a unit volume of a structure when it is stressed to its proportional limit. Brittle materials do well under compressive forces, however, because they tend to close cracks. Most web browsers block content or generate a “mixed content” warning when users access web pages via HTTPS that contain embedded content loaded via HTTP. Numeric tags are not allowed. Dental restorative materials are used to replace tooth structure loss, usually due to dental caries (dental cavities), but also tooth wear and dental trauma.On other occasions, such materials may be used for cosmetic purposes to alter the appearance of an individual's teeth.. (59 month(s) ago), Hi i need this ppt please. m ½ MN .m -3/2 Because fracture toughness relates to crack propagation as opposed to crack initiation, surface condition is of little importance. Materials Science and Engineering: C, Volume 106, 2020, Article 110167. Change in the mechanical, thermal and catalytic properties of the materials can be seen with the increase in surface area to volume ratio at the nanoscale level. 4 Examples of density of some dental materials. Therefore, we studied mechanical properties of series organic nano cocrystals primarily consisting of trans-1,2-bis(4-pyridyl)ethylene and substituted resorcinol using AFM nanoindentation technique. Restorative dental materials, Craig 12 th edition Dental Materials & their selection by William J. O’Brein 4 th edition Fundamentals of colour by Stephan.J.Chu Esthetics in dentistry, by Goldstein Esthetic dentistry:An artists science, Sharat reddy and Ratnadep Patil . © 2014 authorSTREAM. • Water absorption (W w): The amount of water absorbed by a material when immersed in water for a period of time. To prevent users from facing this, Use HTTPS option. Physical Properties 1. i.e. muhammad334316 Viscosity M… Biting force - generally higher for males than females. Bachelor’s degree (minimum 2.2 or equivalent) in a subject related to dentistry or materials science MPa . drmanikantansasi send me at klaira73@gmail.com the material used for the prosthesis. While it is understandable that there is bound to be some amount of tissue reaction due to the introduction of a foreign substance, the resulting changes in mechanical, physical, and chemical properties within the localized environment should not lead to local delete-rious changes and harmful systemic effects. College of Dental Medicine, Ft. Lauderdale, FL 33328-2018 jeffthom@nova.edu We will approach all of the major categories of ceramic properties in this module – physical, chemical, and mechanical – with key examples for each one. Example : a cobalt chromium partial denture alloy has 1.5 % elongation but UTS of 870 MPa .PowerPoint Presentation: DUCTILITY Ability of materials to sustain a large permanent deformation under a tensile load before it fractures. Units : joules, foot-pounds, inch–poundsPowerPoint Presentation: IZOD IMPACT TESTER The specimen is clamped vertically at one end. Density is the mass per unite volume of the material .its units are gm/cm³ and pound/in³. Useful property because it is easier to measure.PowerPoint Presentation: For brittle materials such as composites and ceramic - Yield strength can’t be measuredPowerPoint Presentation: DIAMETRAL TENSILE STRENGTH Tensile strength is determined usually by subjecting a load, wire etc. In Craig's Restorative Dental Materials (Fourteenth Edition), 2019. to tensile loading ( Uniaxial tension test). But if both the values are low, impact resistance is also low. All rights reserved. Optical Properties V. Mechanical Properties I. 1.3.2 Physical properties (7) 1.3.2.1 Hydro-physical properties • Hygroscopicity: is the capacity of a product (e.g. Rank of Resilience Material Elastic modulus ( Gpa ) Tensile strength ( Mpa ) 1 Composite Resin 17 30 – 90 2 Dental porcelain 40 50 – 100 3 Polymethyl methacrylate 3.5 60 4 Amalgam 21 27 – 55 5 Alumina ceramic 350 - 418 120MASTICATION FORCES AND STRESSES: MASTICATION FORCES AND STRESSES Because of their dynamic nature, biting stresses during mastication are difficult to measure. (87 month(s) ago), pls send me this ppt to my mail id, drmanikantanmds@yahoo.com, By: Cram.com makes it … 3) Percent elongation after fracture.PowerPoint Presentation: An increase in temperature decreases ductility because a material's strength generally decreases with an increase in temperature. Used for materials that exhibit predominantly elastic deformation & no plastic deformation.PowerPoint Presentation: Method : A compressive load is placed by a flat plate against the side of a short cylindrical specimen or disk. Applications of Nanocomposite Materials in Dentistry, 2019, pp. CiteScore: 8.0 ℹ CiteScore: 2019: 8.0 CiteScore measures the average citations received per peer-reviewed document published in this title. This property is generally independent of any heat treatment or mechanical treatment that a metal or alloy has received but is dependent on the composition of the material.Poisson’s Ratio: Poisson’s Ratio For an ideal isotropic material of constant volume the ratio is 0. Mechanical Properties of Dental Materials - Dr. Nithin Mathew MECHANICAL PROPERTIES BASED ON ELASTIC DEFORMATION • Mechanical properties that are measures of the elastic strain of dental materials includes: • Young’sModulus / Modulus of Elasticity • Dynamic Young’s Modulus • Shear Modulus • Flexibility • Resilience • Poisson’s Ratio 31 Physical Properties of Dental Materials* ... Prosthodontics dental materials: From conventional to unconventional. Dependence of mechanical properties and SCSC reactivity on the resorcinol structure is also investigated as well. Materials that are brittle usually have a very ordered atomic structure which does not permit the easy movement of dislocations. The most important physical properties of. Other properties that are determined from … A drastic change in theproperties of nanomaterialscan be observed when they are breakdown to the nanoscale level. Properties of materials We shall concern ourselves with three types of issues: (a) Mechanical properties of materials (strength, toughness, hardness, ductility, elasticity, fatigue and creep). 285-305. kZÄ The energy lost by the pendulum during the fracture of the specimen can be determined by the comparison of the length of the swing after the impact with that of its free swing when no impact occurs. OF DENTAL MATERIALS INTRODUCTION. You do not have the permission to view this presentation.   Emerging Materials Research covers materials process, structure, properties and performance at the macro micro and nanoscale. Eg : Amalgam, Ceramics & Composites are brittle at oral temperature 5 -55°C. Quickly memorize the terms, phrases and much more. Disadvantages :Barcol hardness test: Barcol hardness test Depth of cure of resin composites. Biological properties of Dental materials 1, Copy of Biological properties of Dental materials 1, 18 Mechanical Properties Which Every Mechanical Engineer, Mechanical material and Ceramic Mosaic Floor, PHYSICO-MECHANICAL PROPERTIES OF COAL BEARING STRATA, Physico mechanical properties of rock materials, effect-of-reclaim-rubber-loading-on-the-mechanical-properties-of-sbr-c. Physical Properties II. Hence they are brittle.PowerPoint Presentation: Brittle materials are sensitive to internal flaws/cracks/voids and do not respond well to tensile or bending forces because these forces tend to propagate the flaws/cracks/voids. Moreover, photolithography on the Physical nature of material is described by various properties , all of which play a role in defining its applications and limitations in dentistry . „{n[8mE™ÃŸŒ@ȁÒBºöAܜìüXjTÛbSý”Õ¶OF@¤ås0¡õî®F\È ÓäΈ–õ®OÅ,,榮‹Ã@"C! Toughness depends on strength and ductility. Amalgam and Casting Alloys. This test is known as three-point bending test .PowerPoint Presentation: FATIGUE STRENGTH When a stress is repeated a great number of times , the strength of the material may be drastically reduced and ultimately cause failure. At present, there is no systematic review, which supports the clinicians’ criteria, in the selection of a specific material over another for a particular clinical situation. Thermal Properties III. 2) Maximum number of bends performed in a Cold bend test. With appropriate values for velocities and masses involved, a blow by fist to jaw can be considered an impact situation.PowerPoint Presentation: A material with low elastic modulus and high tensile strength is more resistant to impact forces. This chapter focuses on the physical and mechanical properties. The vertical force produces a tensile stress along the side of the disc that is perpendicular to the vertical plane that passes through the centre of the disk. CeramicKnoop hardness test: Knoop hardness test Rhombohedral pyramid diamond Indentation - Rhombic Length of the largest diagonal is measured.PowerPoint Presentation: Ideal for measurement of elastic materials Advantages : same as the Vickers test. However it is different for different regions in the mouth and also from person to person. deemah34 Ductility is unrelated to proportional limit. ‘:®­ ¥ÉÜR†5#†˜ðY>݉}—ÝBú˜fE™å±±4…Hµ@ÉÄ4•Y˜S8VÖ04 †Y-›"“j¨‚–&sS™“ Units : m.MN / m 3 - represents energy per unit volume of materialPowerPoint Presentation: A high modulus of resilience is desirable for orthodontic wires - they are capable of storing energy which may then be delivered over an extended period of time.STRENGTH PROPERTIES: STRENGTH PROPERTIES Strength is the stress that is necessary to cause fracture or a specified amount of plastic deformation.PowerPoint Presentation: PROPORTIONAL LIMIT The proportional limit is defined as the greatest stress that a material will sustain without a deviation from the linear proportionality of stress to strain.PowerPoint Presentation: ELASTIC LIMIT The maximum stress that a material will withstand without permanent deformation. Mechanical properties and parameters that are measures of the elastic strain or plastic strain behavior of dental materials include elastic modulus (also called Young’s modulus or modulus of elasticity), dynamic Young’s modulus (determined by the measurement of ultrasonic wave velocity), shear modulus, flexibility, resilience, and Poisson’s ratio. by comma or enter. Physical Properties A. Density. rockytns Physical, Mechanical and Surface Properties of Dental Resin-composites A thesis submitted to the University of Manchester for the degree of Doctor of Philosophy In the Faculty of Medical and Human Sciences 2013 Ali Awad Alrahlah School of Dentistry Mechanical Properties of Dental Materials Colloidal systems Two or more phases with one highly dispersed on the other. Therefore, the greater the ductility and the lower the yield strength, the greater the burnishabilityPowerPoint Presentation: MALLEABILITY Ability of a material to sustain permanent deformation without rupture under compression as in hammering or rolling into a sheet Gold is the most malleable, second is silver & aluminium third An increase in temperature generally results in a increase in malleability because malleability is dependent upon dislocation movement, and dislocations generally move more easily at a higher temperature.PowerPoint Presentation: Ductility Malleability Gold Gold Silver Silver Platinum Aluminium Iron Copper Nickel Tin Copper Platinum Aluminium Lead Zinc Zinc Tin Iron Lead NickelPowerPoint Presentation: HARDNESS In mineralogy the relative hardness of a substance is based on its ability to resist scratching. (b) Physical properties (density, specific heat, melting and boiling point, thermal expansion and conductivity, electrical and magnetic properties) A brittle material may not necessarily be weak. II. Most material s have some - Dental Materials. CiteScore values are based on citation counts in a range of four years (e.g. It is measured by subjecting a beam of the material to three- or four-point loading which results in the development of compressive stresses on the top of the beam, tensile stresses on the bottom, and shear stresses on the sides. There are a measure of strength and lasting characteristics of the material in service and are of good importance in the design of tools, machines, and structures.. (77 month(s) ago), pls send dis ppt to my mail..its rufus.benaud11@gmail.com, By: PROPERTIES OF DENTAL MATERIALS I. Mechanical properties of dental materials By, Dr.S.H.Karthick , II yr PG, Department of Conservative Dentistry & Endodontics PowerPoint Presentation: Mechanical properties Stress Strain Mechanical properties based on elastic deformation Stress-strain diagram Modulus of elasticity Poisson's ratio Flexibility Resilience Enter one or more tags separated Copy, By: For some materials stress can be loaded infinite number of times without failure - Endurance Limit .PowerPoint Presentation: The imperfections lead first to the development of micro-cracks, which coalesce and ultimately lead to a macroscopic crack and failure.PowerPoint Presentation: A rough brittle material would fail in fewer cycles of stress.PowerPoint Presentation: IMPACT STRENGTHPowerPoint Presentation: Charpy -Type impact tester A pendulum is released that swings down to fracture the centre of a bar specimen that is supported at both ends. Fatigue - defined as a progressive fracture under repeated loading. PHYSICAL, THERMAL, AND MECHANICAL PROPERTIES OF POLYMERS A1.1 PHYSICAL PROPERTIES Physical properties of polymers include molecular weight, molar volume, density, degree of polymerization, crystallinity of material, and so on. The property is often described as "springback potential ." contact the author of the presentation. A tough metal may be strong, but a strong metal may not be tough.PowerPoint Presentation: FRACTURE TOUGHNESS A measure of the resistance of a material to failure from crack propagation in tension. • Metallic maxillary prosthesis should be as thin as possible 2. Materials scientists learn about these mechanical properties by testing materials. One way that ductility is used in dentistry is as a measure of Burnishability . Physical properties are based on laws of mechanics optics , acoustics, thermodynamics ,electricity , rheology , magnetism , radiation ,atomic structure and nuclear phenomenon etc. amalgam are flow and creep, dimensional change, and strength. The 3rd edition of ‘Dental Materials (Principles and Applications)’ by Zohaib Khurshid and his co-editor is an up-to-date information manual in the field of dental material science. Gold is the most ductile metal, second is silver and Platinum comes third in ductility.PowerPoint Presentation: MEASUREMENT OF DUCTILITY There are 3 common methods for measurement of ductility: 1) Reduction in area of tensile test specimens. (A) It is a measure of how a material behaves when under multiple stresses. 64PowerPoint Presentation: Thank you. )n¨®ËºM±°±$¹Dµw—iÉOúÉ»ø@O¢˜ª³MŒIµSAK“¹©lxèùP›zÑÈ-€…]Qûm%)ªÝׁL. 39 Region Biting force Molar 400 to 890N Premolar 222 to 445N Incisor region 89 to 111NPowerPoint Presentation: TOUGHNESS Defined as the amount of elastic and plastic deformation energy required to fracture a material. 1øžànp2Î46%ª©­B–sSWÐâ®sD¯áã8t ëžavDZ­,…F¤"r´-Û-À.€™ð~©ÒȐT?%³´˜[º†G*®è>f'pKWD]àí7–¢P¨ÂځLÍÇKâ@÷Ž'm„ guide to dental materials and devices including information on the use properties and or characteristics of Nov 11, 2020 Posted By John Creasey Library TEXT ID 8107a3595 Online PDF Ebook Epub Library paffenbarger is director emeritus of the american dental research unit at the national bureau of standards dental materials are used in different treatments such as plaque Start studying Physical and Mechanical Properties of Dental Materials. Eg: .Orthodontic Bracket removalFlexural (bending) stress: Flexural (bending) stressPowerPoint Presentation: Strain Strain = Change in Length / original length Strain (  ) = Deformation / = L – Lo / Lo =  L/ Lo original lengthStrain: Elastic or Plastic: Strain : Elastic or PlasticMECHANICAL PROPERTIES BASED ON ELASTIC DEFORMATION: MECHANICAL PROPERTIES BASED ON ELASTIC DEFORMATION STRESS-STRAIN DIAGRAMPowerPoint Presentation: HOOKE’S LAW (1678)MODULUS OF ELASTICITY : MODULUS OF ELASTICITY Relative rigidity or stiffness of the material within elastic range Young’s modulus of elasticity Elastic modulus = Stress Strain Units : MPa or GPa ( 1 GPa = 1000 MPa )PowerPoint Presentation: Material with a steep line - higher modulus (more rigid).PowerPoint Presentation: Modulus is a reflection of the strength of the inter-atomic or intermolecular bonds. Study Flashcards On Chapter 3 - Physical and Mechanical Properties of Dental Materials at Cram.com. Flash 5 Most engineering material have values of 0.3 Siméon Denis Poisson (1781-1840)PowerPoint Presentation: Material Poisson’s ratio Amalgam 0.35 Zinc phosphate cement 0.35 Enamel 0.30PowerPoint Presentation: FLEXIBILITY Ability of a material to return to its original form indicates its elasticity, but the strain taking place at elastic limit is known as flexibility. Copy, Automatically changes to Flash or non-Flash embed, WordPress Embed Compressive stresses convert to tensile ones through the neutral axis along the center of the beam .PowerPoint Presentation: To evaluate flexural strength of a dental material, it is generally used bar-shaped specimens with dimension of 25 mm in length X 2 mm in width X 2 mm in height Specimens are placed on two supports and a load is applied at the center. Primary Clinical Dental qualification which entitles them to register as a dental practitioner with the General Dental Council in the UK (or) 2. Films based on Salvia hispanica and clove oil: physical, optical and mechanical properties. Here the tensile stress is directly proportional to the compressive load applied.PowerPoint Presentation: FLEXURAL STRENGTH (TRANSVERSE STRENGTH OR MODULUS OF RUPTURE ) Ability to bend before it breaks. Download PDF View details. ... Biosurfaces: A Materials Science and Engineering Perspective,FirstEdition. Mechanical engineers calculate those forces and material scientists how materials deform (elongate, compress, twist) or break as a function of applied load, time, temperature, and other conditions. Then, the theories and important results of the mechanical properties between nanoparticles or the nanoparticles acting on a surface, e.g., hardness, elastic modulus, adhesion and friction, as well as movement laws are surveyed. Biocompatibility of amalgam as a dental restorative material is thought to be determined largely by the corrosion products released while in service. Customize Embed, Thumbnail: Mechanical Properties in Design and Manufacturing •Mechanical properties determine a material’s behavior when subjected to mechanical stresses Properties include elastic modulus, ductility, hardness, and various measures of strength •Dilemma: mechanical properties desirable to the designer, such as high strength, usually make Learn vocabulary, terms, and more with flashcards, games, and other study tools. Provisional restorations represent an important phase during the rehabilitation process, knowledge of the mechanical properties of the available materials allows us to predict their clinical performance. Dynamic Mechanical stability of dental materials. The amount or mass of a material in a given volume is the density of the material. Title: Physical properties of dental materials 1 Physical properties of dental materials 2 The elements of study. It primarily centers around static bodiesPowerPoint Presentation: STRESS Stress = Force/ Area SI units: MPa or psiTypes of stresses: Types of stresses Compressive stress compress or shorten Tensile stress stretch or elongatePowerPoint Presentation: Shear stress A stress that tends to resist the sliding or twisting of one portion of a body over another. The average maximum sustainable biting force is approximately 756N. Embed: cargo, packaging material) to react to the moisture content of the air by absorbing or releasing water vapor. Dental Materials Lectures, University of Michigan, Stephen C. Bayne. \¬42$×NÁ,-斮  eƒÌHž,µÛ®\ÓåÚÉËRˆ”ž“‰›K8šqøŠ]cjI§l[•ëTÈÒbnêò¦Qìq$ÆÈ>(îæn•!6•¥Ô¨º~J âD«$Õ»8û î9‹Ñí«42$×OÁ,-æ–.sÓ8&i²éÛE«†ÅŒ@Èώá@ÊÙ&•`6>æ-5ªÑ;#l¬B£œÙ2"¡ Applicants must hold either a: 1. The following online modules for dental materials instruction are OPEN SOURCE for free use of anyone as long as all appropriate credits are provided during their use to recognize the authors. Burnishability Index is defined as the percentage elongation divided by the yield strength. For all practical purposes, the same as the proportional limit.PowerPoint Presentation: YIELD STRENGTH Defined as the stress at which a material exhibits a specified limiting deviation from proportionality of stress to strain. in this video you can learn about the Mechanical Properties of Dental Materials. The mechanical properties of metals are determined by the range of usefulness of the metal and … Fatigue strength - the stress at which a material fails under repeated loading.PowerPoint Presentation: Failure under repeated / cyclic loading is therefore dependent on, The magnitude of the load and The number of loading repetition. These properties are expressed most often in units of stress and strain.