Nanoscience: Mechanical Properties

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Diagram. I. Excellent Mechanical PropertiesII. Nanostructured MaterialsIII. Conclusions and Applications. Ductile test. Determination of mechanical propertiesStress: s = F/SStrain: e = ?l/l0. Ductile Test bend. . Commonplace Tensile Test bend or Strain Stress bend. Flexible Deformation. .

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Nanoscience: Mechanical Properties Olivier Nguon CHEM *7530/750 Feb 21st 2006

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Outline I. Great Mechanical Properties II. Nanostructured Materials III. Conclusions and Applications

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Tensile test Determination of mechanical properties Stress: σ = F/S Strain: ε = Δ l/l 0

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Stress, σ (Mpa) Max stress : rigidity Necking Max flexibility: Yield quality Fracture Strain, ε (%) Elastic twisting Plastic disfigurement Tensile Test bend Typical Tensile Test bend or Strain Stress bend

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Modulus = slant Strain Elastic Deformation Hooke's law: σ = E ε E = Young modulus (Pa) Stiffness of material Non direct models exist (visco-versatile conduct) Stress, σ

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Mechanical properties Yield quality: greatest worry before lasting strain Tensile quality: most extreme anxiety Ductility: measure of misshapening (L f – L o )/L o Toughness: capacity to absorbe vitality: territory under bend

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Hardness Resistance to plastic distortion Measure of profundity or size of space

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II. Nanostructured materials

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Nanoparticles Conventional materials: Grain estimate micron to mm Nanoparticles increment grain limits Influence on mechanical properties: Increased hardness, yield quality, flexible modulus, strength

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Comparison ductile bends Comparison: Al Mg cryomilled (20 nm) Al Mg ultra fine grain (80 nm) Al Mg coarse (2 mm) Cryomilling: Milling in fluid N 2 Ultrafine grain: electrodeposition B. Han, Red.Adv.Mater.Sci ; 9 (2005) 1-16

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Mechanical properties of nanomaterials contrasted with coarse grain materials Higher Young modulus and elasticity (to 4 times higher) Lower plastic misshapening More weak

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Strength and Hardness with grain measure Strength and Hardness of nanostructured material increments with diminishing size Grain limits distortion

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Comparison of Young modulus

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Elongation nanostructured materials Elongation diminished Lower thickness of versatile disengagements Short separation of disengagement development

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III. Conclusions

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Mechanical properties Mechanical properties: Strength, sturdiness, hardness expanded Materials more weak Due to expanded grain limits thickness and less separations thickness

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Important elements on mechanical properties History of the material: Temperature, strain : impact on measure of disengagements, grain estimate Impurities : isolate at high temperature and influence mechanical properties

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Applications Biomedical: bones, inserts, and so forth. High quality, solid, enduring materials: automotives, gadgets, aviation, and so on. Composites materials