QUANTITATIVEQUANTITATIVEMETALLOGRAPHYMETALLOGRAPHYN. PRAKASANME METALLURGY
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYINTRODUCTIONQuantitative Metallography involvesdetermination of spec...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYMethods:There are two methods used in quantitativemetallography• Com...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYComparison Method It is a quickest method for routine analysis In t...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYMeasurement Methods Microscopic measurements can be made either,• On...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYMeasurement MethodsMeasuring ways are,• Measuring the area of each i...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Particle size and NumberComparison method,• When de...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHY Determination of Particle size and Number Comparison method, Graphi...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Particle size and NumberLinear analysis• Drawing st...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Particle size and NumberPoint counting method (ASTM...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Particle size and NumberPoint counting method (ASTM...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Particle size and NumberPoint counting method (ASTM...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Grain sizeComparison method• It is the simplest met...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Grain size Comparison methodASTM E112 Plate II,Rati...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Grain size Comparison methodASTM E112 Plate III,Rat...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Grain sizePlanimetric method (Jeffries method)• In ...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Grain sizePlanimetric method• The Root of this valu...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHY Determination of Grain size Planimetric method (Jeffries method)
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Grain size Planimetric method (Jeffries method) n1...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Grain sizeIntercept method• It is simple and rapid ...
QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHY Determination of Grain size Intercept method
References:Metallurgical Microscopy by Helfrid Modin &Sten modin,Standards for Metallography by George F.Vander Voort, ...
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Quantitative metallography

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Quantitative metallography

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Quantitative metallography

  1. 1. QUANTITATIVEQUANTITATIVEMETALLOGRAPHYMETALLOGRAPHYN. PRAKASANME METALLURGY
  2. 2. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYINTRODUCTIONQuantitative Metallography involvesdetermination of specific characteristics of amicrostructure by making quantitativemeasurements on micrographs ormetallographic images.Quantities so measured include volumeconcentration of phases, grain size, particlesize and surface area to volume ratio of microconstituents.
  3. 3. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYMethods:There are two methods used in quantitativemetallography• Comparison method• Measurement method
  4. 4. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYComparison Method It is a quickest method for routine analysis In this method, the microstructure image or micrographis compared with series of Standard charts. In Microscopes, facilities are provided for insertingstandard templates which are reproducedsimultaneously with the object, thus making for easyand rapid comparison. The standard charts and templates have been issuedby ASTM, ISO & SIS for,• Grain size measurement• Inclusion rating• Determination of porosity in sintered carbides• Classification of graphite structure in Cast irons.
  5. 5. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYMeasurement Methods Microscopic measurements can be made either,• On the virtual image in the microscope• On the micrograph• On the ground glass screen Advanced microscope with image analyzing facilitiesgive fully automatic quantitative measurements. The measuring methods are,• By comparison with charts or templates• By means of square grid
  6. 6. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYMeasurement MethodsMeasuring ways are,• Measuring the area of each individual particleor grain. Then measured areas are dividedby the square of the linear magnification.• Drawing straight lines on the image projectedon the ground glass screen or micrograph.The average grain size is the total length ofthe lines divided by number of grainsintercepts and by the linear magnification.
  7. 7. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Particle size and NumberComparison method,• When determining particle size and size distributionof powders, inclusion etc., the area, diameter orlength of each individual particle is measured.• The standard reference template is placed over theimage projected on the microscope ground glassscreen or micrograph.• Each particle is then classified in accordance withsuch templates.
  8. 8. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHY Determination of Particle size and Number Comparison method, Graphite Shape comparison as per ASTM A247
  9. 9. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Particle size and NumberLinear analysis• Drawing straight lines on the image or micrograph,the length of all intercepts for a certain phase aresummated.• The Ratio between the summated length and thetotal length of the lines is equal to the volumefraction which occupies the structure.
  10. 10. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Particle size and NumberPoint counting method (ASTM E 562)• A standard grid containing large number of points isplaced on the image or micrograph.• The number of points which coincide with the phase,in comparison with the total number of grid pointsgives the surface proportion (or volume fraction) ofthe phase.• For accuracy, large number of grid points must beused.
  11. 11. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Particle size and NumberPoint counting method (ASTM E 562)
  12. 12. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Particle size and NumberPoint counting method (ASTM E 562)• The grid consists of 100 points• 7 “points” were inside the constituent of interest. So,the point fraction is calculated as:
  13. 13. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Grain sizeComparison method• It is the simplest method in determining grain size.• For spherical, equiaxed grains standard charts areavailable from ASTM (ASTM E 112).• For Elongated grains reference charts also available,but usually other methods like Planimetric andintercepts methods are used.• A round , polished and etched specimen surface iscompared with standard charts and templates.
  14. 14. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Grain size Comparison methodASTM E112 Plate II,Rating of Grain size ofAustenitic Twinned alloy
  15. 15. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Grain size Comparison methodASTM E112 Plate III,Rating of Austenitic Grainsize of copper alloy
  16. 16. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Grain sizePlanimetric method (Jeffries method)• In this method a Circle or rectangle of known area isdrawn on the image on the ground glass screen ormicrograph.• A magnification should be selected such that at least50 grains are thus enclosed.• In counting, half the number of grains which are cutthe confining lines is added to number of grainsinside the area.• The average grain area=Total surface areaNo.of grains x surface magnification (M2)
  17. 17. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Grain sizePlanimetric method• The Root of this value is designated as the averagegrain size.• For elongated grains, determination should be madein three section surfaces which right angles to eachother. The number of grains per cubic millimeter isN = 0.7 (n1 x n2 x n3)1/2where, n1, n2, n3 are three planes of intersection
  18. 18. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHY Determination of Grain size Planimetric method (Jeffries method)
  19. 19. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Grain size Planimetric method (Jeffries method) n1= number of grains completely inside the test circle n2= number of grains intercepting the circle f = Jeffries multiplier; f = magnification2/circle area Magnification 100X NA = Average Grain area
  20. 20. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHYDetermination of Grain sizeIntercept method• It is simple and rapid than Planimetric method.• In this method, the number of grains which are cut bystraight lines are measured.• The total length of the straight line is divided by theNo. of grains cut by the lines and by the linearmagnification.• The total length of the straight line drawn should cutat least 50 grains.• In elongated grains, measurement is carried out inthree directions at right angles & one is parallel toelongated direction. The Number of grains/Cmm isN = 0.7 (n1xn2xn3)
  21. 21. QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHY Determination of Grain size Intercept method
  22. 22. References:Metallurgical Microscopy by Helfrid Modin &Sten modin,Standards for Metallography by George F.Vander Voort, Director, Research &Technology Buehler Ltd.QUANTITATIVE METALLOGRAPHYQUANTITATIVE METALLOGRAPHY

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