2. SCHEMATIC REPRESENTATIONS OF THE DIFFERENT ASPECTS OF METAL IN DIFFERENT STEPS

3. Step1 First differences in metal appear as shape, colour and weight

4. Step 2- after proper preparation A group of cells called crystals appear in random shapes and sizes

5. Third step- Crystals, composed of small particles called atoms. Atoms are arranged in a definite pattern

6. Fourth step Orderly arrangement of atoms form crystallographic planes which are alligned along the three dimensions

7. Fifth step Particles within a crystal are called atoms

8. Sixth step Atoms are positioned in solids in an orderly arrangement. Imaginary lines drawn through the centre of adjacent atoms form geometric shapes BCC FCC HCP

9. Seventh step Atoms are composed of the same particles. Difference in atoms is in the number of particles and arrangement.

10. ATOMS AVERAGE SIZE 1 X 10 -7 mm CONSISTS OF A MASSIVE CORE- NUCLEUS SURROUNDED BY NEGATIVE ELECTRIC CHARGES- ELECTRONS NUCLEUS WITH PROTONS & NEUTRONS ATOMS ELECTRICALLY NEUTRAL ELECTRONS REVOLVE IN DEFINITE ORBITS (PAULI EXCLUSION PRINCIPLE- 2 electrons in 1 orbit)

11. Properties of metallic elements CHEMICALPHYSICALMECHANICAL Related to structural arrangement of particles. Eg: no: of shells, no: of protons, TABLE Related to behaviour of atomic structure- wt/unit volume, rate of heat transfer, electrical resistance, thermal expansion, melting temperature etc. Examined and evaluated by observing materials’ reaction to application of force. Eg: hardness, strength, ductility, fatigue etc.

12. STRUCTURE OF METALS - The important aspect of any material Relationship between structure and properties to be studied Metallic objects -an aggregate of many small crystals - POLYCRYSTALLINE Crystals in these materials referred to as GRAINS Examination of structure with microscopes of 100X to 1000X and above This study called MICROSTRUCTURE study - This study is of great use to a metallurgist - This study is of great use to a metallurgist

13. . ZOOM ZOOM POWER OF 10 FROM MICRO TO MACROCOSMOS

14. This is a trip at high speed, jumping distances by factor of 10. Start with 10 0 equivalent to 1 meter, and increasing sizes by factor of 10s,or 10 1 (10 meters), 10 2 (10x10 = 100 meters, 10 3 (10x10x10 = 1.000 meters), 10 4 (10x10x10x10 = 10.000 meters), so on, until the limit of our inmagination in direction to the macrocosmos. Later let’s return, a little faster, up to the point where we started and continue our trip in the opposite direction reducing distances of travel by factors of 10 into the microcosmos. Observe the constancy of the laws of the universe and think about how much the human race still needs to learn...

15. BON VOYAGE!

16. Distance to a bunch of leaves, in the garden 10 0 1 meter

17. Start our trip upwards.... We could see the foliage. 10 1 10 meters

18. At this distance we can see the limits of the forest and the edifications 10 2 100 meters

19. We will pass from meters to kilometers.. Now it is possible to jump with a parachute... 10 3 1 km

20. The city could be observed but we really can not see the houses 10 4 10 km

21. At this height, the state of Flórida - USA, can be seen.. 10 5 100 km

22. Typical sight from a satellite 10 6 1.000 km

23. The north hemisphere of Earth, and part of South America 10 7 10.000 km

24. The Earth starts looking small... 10 8 100.000 km

25. The Earth and the Moon’s órbit in white.... 10 9 1 millón de km

26. Part of the Earth’s Orbit in blue 10 10 Millons de km

27. 10 11 100 millons de km Órbits of: Venus and Earth...

28. Órbits of: Mercury, Venus, Earth, Mars and Júpiter. 10 12 1 billón de km

29. At this height of our trip, we could observe the Solar System and the orbits of the planets 10 13 10 billons de km

30. 10 14 100 Billons de km The Solar System starts looking small...

31. The Sun now is a small star in the middle of thousands of stars... 10 15 1 trillón de km

32. At one light-year the little Sun star is very small 10 16 1 light-year

33. Here we will see nothing in the infinity.... 10 17 10 light-year

34. “Nothing” Only stars and Nebulae... 10 18 100 light-years

35. 10 19 1,000 light-years At this distance we started travelling the Via-Láctea (Milky Way), our galaxy.

36. We continued our travel inside the Via-Láctea. 10 20 10,000 light-years

37. We started reaching the periphery of the Via-Láctea 10 21 100,000 light-years

38. At this tremendous distance we could see all the Via-Láctea & other galáxies too... 10 22 1 millión light-years

39. From this distance, all the galaxies look small with inmense empty spaces in between. The same laws are ruling in all bodies of the Universe. We could continue traveling upwards with our imagination, but now we will return home quickly 10 23 - 10 million light-years

40. 10 22

41. 10 21

42. 10 20

43. 10 19

44. 10 18

45. 10 17

46. 10 16

47. 10 15

48. 10 14

49. 10 13

50. 10 12

51. 10 11

52. 10

53. 10 9

54. 10 8

55. 10 7

56. 10 6

57. 10 5

58. 10 4 Questions that come to our minds... Who are we? Where are we going? From where did we come from?

59. 10 3 Or... What do we represent in the Universe?

60. 10 2 In this trip “upwards” we went to the power of 23 of 10

61. 10 1 Now we are going to dig inside of the matter in an inverse trip...

62. We arrived at our starting point. We could reach it with our arms... 10 0

63. Getting closer at 10 cm...We can delineate the leaves. 10 -1 10 Centímeters

64. At this distance it is possible to observe the structure of the leaf. 10 -2 1 Centímeter

65. The cellular structures start showing... 10 -3 1 Millímeter

66. The cells can be defined. You could see the union between them. 10 -4 100 microns

67. Start our trip inside the cell... 10 -5 10 microns

68. The nucleus of the cell is visible. 10 -6 1 micrón

69. Again we changed the messuring unit to adapt to the minúscule size. You could see the chromosomes. 10 -7 1.000 Angstroms

70. In this micro universe the DNA chain is visible. 10 -8 100 Angstroms

71. ...the chromosómes blocks can be studied. 10 -9 10 Angstroms

72. It appears like clouds of electrons... These are carbon átoms that formed our world. You could notice the resemblance of the microcosmos with the macrocosmos... 10 -10 1 Angstrom

73. In this miniature world we could observe the electrons orbiting the atoms. 10 -11 10 picómeters

74. An inmense empty space between the nucleous and the electron orbits... 10 -12 1 Picómeter

75. At this incredible and minuscule size we could observe the nuceous of the atom. 10 -13 100 Fentómeters

76. Now we could observe the nucleous of the carbon atom 10 -14 10 Fentómeters

77. Here we are in the field of the scientific imagination, face to face with a proton. 10 -15 1 Fentómeter

78. Examine the ‘quark’ partícules There is nowhere more to go... At the limits of current scientific knowledge. This is the limit of matter... 10 -16 100 Atómeters

79. And now...Are you the center of the universe? Are you the special creature of the Creatión? What is behind those limits? Are there any limits? Note that going “downwards” we could only go to the power of minus 16ªof 10 and reached the (known?) limits of matter... But upwards we went to the power of 23ª of 10 and stopped... But really we could have continued our trip with out limits to our imagination!!!!... then?...who says that we are alone in the universe?

80. SCHEMATIC REPRESENTATIONS OF THE DIFFERENT ASPECTS OF METAL IN DIFFERENT STEPS FFFFirst differences in metal appear as shape, colour and weight AAAA group of cells called crystals appear in random shapes and sizes CCCCrystals, composed of small particles called atoms. Atoms are arranged in a definite pattern OOOOrderly arrangement of atoms form crystallographic planes which are aligned along the three dimensions PPPParticles within a crystal are called atoms AAAAtoms are positioned in solids in an orderly arrangement. Imaginary lines drawn through the centre of adjacent atoms form geometric shapes AAAAtoms are composed of the same particles. Difference in atoms is in the number of particles and arrangement.

81. Properties of metallic elements 1. C HEMICAL – related to structural arrangement of particles 2. P HYSICAL- related to behaviour of atomic structure 3. M ECHANICAL- examined and evaluated by observing the reaction of material

82. METALLOGRAPHIC SPECIMEN PREPARATION THIS IS AN ART TECHNIQUES VARY FROM ONE LAB TO ANOTHER TECHNIQUES VARY FROM ONE LAB TO ANOTHER VARIATION IN PROCEDURE DEPENDING ON METAL TO BE EXAMINED BUT, BASIC OPERATIONS SIMILAR With iron and steel as specimen, methods explained With iron and steel as specimen, methods explained

83.  Cut the object and prepare a flat surface on one side of specimen  Mount specimen in a small plastic disc (25 mm dia and 12 mm thick)  Expose surface on one side of disc - For this,place specimen inside the ring mould, pour epoxy resin into mould and fill the ring, allow resin to harden, and finally invert.

84. Four basic steps on this specimen Fine Grinding Rough polishing Final polishing Etching Plastic disc Metal Specimen Reduces thickness of the deformed layer below the specimen surface

85. Fine Grinding  Grinding using silicon carbide powders bonded onto specially prepared papers.  Specimen hand rubbed against the abrasive paper laid on a flat surface (or on horizontal flat rotating wheels) (or on horizontal flat rotating wheels)  Surface lubricated with water- for flushing action  Three grades of abrasives used- 320, 400, 600 grit( size 33, 23, 17 microns)  Movement of specimen in one direction only  From one paper to another, the specimen rotated through 45 0 to have new scratches on previously cut. Continued till scratches from preceding stage disappears.

86. Rough polishing  Critical stage.  Abrasive is powdered diamond dust of 6 microns  Powder in an oil- soluble paste  Small quantity placed on nylon cloth- covered surface of rotating polishing wheel  Lubricant- specially prepared oil  Specimen pressed against cloth with considerable pressure  Not held in a fixed position, but moved around the wheel in direction opposite to rotation.  Thus, more uniform polishing action.  Diamond particles remove deep layer of deformation remaining from fine grinding

87. Final polishing  Fine scratches and thin distorted layer from rough polishing stage removed.  Alumina powder Al 2 O 3 (gamma form) of 0.05 micron used.  Placed on cloth covered wheel, distilled water used as lubricant.  Cloth contains nap.  A scratch free surface with no detectable layer of distorted metal obtained.

88. Etching  After final polishing, granular structure not seen under microscope. Grain boundaries have thickness of the order of a few atoms. Resolving power of microscope too low to reveal this.  ETCHANT used to make the boundary visible.  Polished surface immersed in a weak acidic or alkaline solution.  Eg: NITAL- 2% nitric acid in alcohol. (or applied by rubbing with cotton swab wetted with etchant.) (or applied by rubbing with cotton swab wetted with etchant.)  Metal dissolved from metal surface. Attacks grain boundaries more rapidly.  Shallow steps on the surface reveal the boundaries. Vertical surfaces will not reflect in the same fashion as smooth horizontal surface.

89. Reveals crystal boundaries Before etching After etching

90. Electro-polishing and electro-etching  In some metals- stainless steel, titanium, zirconium etc.- distorted layer removal difficult. Mechanical polishing not successful.  Polished by electropolishing technique. Specimen made anode and insoluble material used as cathode in an electrolytic bath. With proper current density, specimen surface is dissolved. (bath and current controlled)  When composition of bath and current density varied, procedure is electro-etching.

91. The most commonly used etchants EtchantCompositionConc.ConditionsComments Kalling's No. 1 Distilled water CuCl2 Hydrochloric acid Ethanol 33 ml 1.5 gram s 33 ml 33 ml Immersion etching at 20 Degrees Celcius For etching martensitic stainless steels. Martensite will be dark and the ferrite will be colored. Kalling's No. 2 CuCl2 Hydrochloric acid Ethanol 5 grams 100 ml 100 ml Immersion etching at 20 Degrees Celcius For etching duplex stainless steels and Ni-Cu alloys and superalloys. Kellers Etch Distilled water Nitric acid Hydrochloric acid Hydrofluoric acid 190 ml 5 ml 3 ml 2 ml 10-30 second immersion. Use only Fresh etchant Excellent for aluminum and alloys immersion for 10-20 seconds ; titanium alloys immersion for 10-20 seconds.

92. EtchantCompositionConc.ConditionsComments Kroll’s Reagent Distilled water Nitric acid Hydrofluoric acid 92 ml 6 ml 2 ml 15 secs Excellent for titanium and alloys. Swab specimen up to 20 seconds. Nital Ethanol Nitric acid 100 ml 1-10 ml Seconds to minutes Most common etchant for Fe, carbon and alloys steels and cast iron - Immerse sample up from seconds to minutes; Mn-Fe, MnNi, Mn-Cu, Mn-Co alloys– immersion up to a few minutes. Marble's Reagent CuSO4 Hydrochlori c acid Water 10 grams 50 ml 50 ml Immerse or swab for 5-60 secs. For etching Ni, Ni-Cu and Ni-Fe alloys and superalloys. Add a few drops of H2SO4 to increase activity.

93. Etchant Compos ition Conc.ConditionsComments Murakami's K3Fe (N)6 KOH Water 10 grams 10 grams 100 ml Pre-mix KOH and water Before Adding K3Fe(CN)6 Cr and alloys (use fresh and immerse); iron and steels reveals carbides; Mo and alloys uses fresh and immerse; Ni-Cu alloys for alpha phases use at 75 Celcius; W and alloys use fresh and immerse; WC-Co and complex sintered carbides. Picral Ethano Picric acid 100 ml 2-4 grams Seconds to minutes Do not let etchant crystallize or dry – explosive Recommended for microstructures containing ferrite and carbide. Vilella’s Reagent Glycerol HNO 3 HCl 45 ml 15 ml 30 ml Seconds to minutes Good for ferrite-carbide structures (tempered martensite) in iron and steel

94. Guide to Acid Concentrations Acid / Base Specific gravity Concentration Nitric (HNO 3 )1.468-70% Hydrofluoric (HF)-40% Hydrochloric (HCl)-37-38% Ammonium Hydroxide (NH 4 OH)-35%

95. Metallographic Etchants Aluminimum alloysHigh carbon Steel Brasses and BronzesStainless Steel Cast IronTin Alloys Copper AlloyaZinc Alloys Low carbon SteelCeramics CAUTION: Safety is very important when etching. Be sure to wear the appropriate protective clothing and observe all

96. METALLOGRAPHIC SPECIMEN PREPARATION-in brief Cut the object and prepare a flat surface on one side of specimen Mount specimen in a small plastic disc (25 mm dia and 12 mm thick) Expose surface on one side of disc - For this, place specimen inside the ring mould, pour epoxy resin into mould and fill the ring, allow resin to harden, and finally invert. Four basic steps on this specimen Fine GrindingRough polishing Final polishingEtching silicon carbide powders bonded onto specially prepared papers water- for flushing powdered diamond dust of 6 microns Powder in an oil- soluble paste specially prepared oil Alumina powder Al 2 O 3 (gamma form) of 0.05 micron distilled water ETCHANT NITAL- 2% nitric acid in alcohol. Electro-polishing and electro- etching

97. Specimen and Mount Holders Specially Designed Specimen Holders For SEM: The specimen holders are designed to improve productivity and allow one to view more than one sample at a time. This saves pump down time, keep chamber cleaner and get more work done. All mounts are machined from solid aluminum and come with spring clips/or setscrews to hold specimens securely. All mounts are made to fit onto the stage and are designed to fit through all standard specimen exchange ports, and have a center-threaded port to accept the Adapter Pins that fits SEM instrument. Adapter A: Overall measurement: 28mm long x 3.1mm diameter (step-up portion is 6.25mm L x 4.8mm diameter), Adapter B: Overall measurement: 28mm long x 6mm diameter, Adapter C: Overall measurement: 34.5mm long x 16mm diameter All adapters have a threaded portion 5mm in length. Three different types of pin adapters, which are threaded and ready to screw on to the base of the holders are available.

98. Universal SEM Sample Holder To hold almost any sample from 3mm to 29mm in diameter plus various odd shaped samples, with the dimensions not greater than 29mm. The samples are easily inserted or removed from the holder. The holder is made from aluminum and is with four removable sample arms so that it can hold very small samples as well, and it provides good electrical contact to the stage. The standard base measures: 48mm x 42mm x 12mm Thick. Vertical Mount for Thin Samples; Flat Base This is designed to hold thin samples vertically in the SEM or any microscope. It is 25mm in diameter and 10mm thick. Each of the two loader jaws can hold up to 3mm thick samples. The spring loader keeps thin samples vertical so that cross sections can be studied. This holder is very useful for cross sections of silicon wafers or multilayer capacitors.

99. Multi Pin Holder The Multi Pin Holder is designed to save time. It accommodates 3 or 5 of ½" dia.(12.5mm) surface, 1/8" dia. (3.1 75910 Specimen Holders For SEM 10-14 mm) pin. ISI DS 130 and 150 First Stage Sample Mounts It is 10mm in diameter, 5mm high, copper sample holder to fit in the first stage of the ISI DS 130 and 150 SEM's. The inner cylinder is height adjustable so that one can adjust the sample to the correct working distance.

100. SEM Sample Holder Set For convenience a SEM Sample Holder Set to fill all needs is available. The set consists of one universal holder, one vertical mount holder for thin samples, one 3-pin and one 5-pin configuration holder with a key for the set screw all in a finely finished wood box. Pin Mount Stub Adapters Made from aluminum, used to adapt 1/8" (3.1mm) pin diameter SEM stubs. Available in 10, 15, 16mm diameter as well.

101. Cross Sectional Holder Made from non-magnetic stainless steel with 3.1mm (1/8") diameter pin and adjustable angle turn- screw. Just insert specimens edge-on and observe the cross section directly Four-Pin Stub Holder It accommodates four pin type, up to 12.5 (1/2") surface specimen stubs, with 1/8" (3.1mm) diameter pin.

102. Five 10mm Stub Holder Accommodates five 10mm diameter specimen stubs, with 1/8" (3.1mm) diameter pin Thin Sample Holder Ideal for examination cross section of thin samples, such as wafers, multi-layer of capacitors, plastics, metals, etc. ½" diameter (12.7mm), 1/8" (3.1mm)dia. pin (3.1mm) with split openings up to ¼" (6.4mm). Available with either 8mm (5/16") pin height or 15mm (9/16") pin height. For ISI, JEOL, TOPCON: Double set screw for a secure holding of the specimen during observation. 15mm(9/16")(dia). x 10mm(3/8")(H), 6.4mm(1/4") split.

103. METALLURGICAL LABORATORY TESTING Metallurgical labs stocked with state-of-the-art of equipment that allows to help in materials selection, characterization, component and process design, qualification, failure analysis, and many other services. Specimen Preparation Automatic grinding and polishing equipment Abrasive cut-off wheels Epoxy and cold mount Large section specimen (up to 9 in.) metallographic preparation Acid and electrolytic polishing/etching techniques Specialized sectioning capability Etching techniques for most common materials Removal of rust and scale prior to failure analysis Microstructural Analysis Optical microscopes: magnification up to 2000x with oil immersion Scanning Electron Microscope Cambridge Stereoscan 360 Windowless EDS capability for microstructural chemical analysis

104. Image Analysis Micro- and macro-digital photographic capability Quantitative image analysis for: –Area fraction –Feature measurement –Modularity –Grain size –Size distribution –Inclusion rating –Crack length Software-based weld profile measurement Conventional & digital macrophotograph capability Materials Testing Hardness testing (Rockwell A, B, C) Microhardness testing (Vickers, Knoop) Magnet-gage for ferrite measurement

105. Weldability Testing Gleeble 1000 Thermal/Mechanical Simulator Universal Varestraint Oberlikon-Yanaco Hydrogen Analyzer with high-temperature measurement capability Heat Treatment 3-cubic ft. convection furnace 12-cubic ft. convection furnace 9-cubic ft. oven Nondestructive Evaluation (NDE) Ultrasonic immersion testing Ultrasonic contact testing Eddy current testing Meandering Winding Magnetometer (MWM) Surface cleanliness monitor (Optical Stimulated Electron Emission [OSEE]) Magnetic particle testing Penetrant testing Baroscope and visual inspection Radiography

106. Thermography STANDARD TESTING SERVICES Tensile Bend Fatigue Charpy impact Fracture toughness (CTOD, J&K) Heat treatment services (stress relief, normalizing ageing) Weld cracking sensitivity tests (WIC, Y-groove, CTS, GBOP) Diffusible hydrogen measurement (Mercury and gas chromatography) Gleeble Thermo-mechanical simulator –Weld simulation CCT curves –Process simulation –Thermal/mechanical simulation –Weldability (Varestraint, Sigmajig) –Microstructural characterization Optical Hardness Feature quantification Weld procedure qualification Residual stress measurements (blind-whole method) –Digital image analysis SEM with –EDS capability –Experimental stress analysis (strain gauging services) –High temperature testing up to 1200°C –Expert failure analysis –Welding services (PQR, test plate fabrication, etc.)

107. LATTICE, UNIT CELL, BRAVAIS LATTICE CO-ORDINATION NUMBER ATOMIC PACKING FACTOR MILLER INDICES

108. METAL IDENTIFICATION TESTS METAL- COMPOSED OF SINGLE METALLIC ELEMENT/ GROUP OF ELEMENTS ALLOY- MADE UP OF TWO OR MORE ELEMENTS, ONE METALLIC METAL- CHARACTERISTICS- BASED ON GENERAL CONDITIONS  CRYSTALLINE WHEN SOLID  GOOD CONDUCTOR OF HEAT & ELECTRICITY  DEFORMS WITH APPLICATION OF STRESS IN PLASTIC MANNER  REFLECTS LIGHT WHEN POLISHED

109. ELEMENT - SMALLEST DIVISIBLE PART OF A SUBSTANCE METAL IDENTIFIATION TESTS - TO SEPARATE COMMON METALS –MAGNETIC TEST –VISUAL OBSERVATION TEST –HARDNESS TEST –SURFACE REFLECTIVITY TEST –WEIGHT PER VOLUME TEST –CHEMICAL REACTION TEST –SPARK TEST ASTM, ASM, Al. Assn., ASME, Society of Automotive Engineers, AWS, ANSI, Aerospace Materials Specification, Federal Specification (WW) etc.

110. MAGNETIC TEST Simple Steel, Ni, Co, - magnetic Cu, Al, Tin, Zn, Cr, Mn- nonmagnetic Exceptions too eg: Stainless steel Corrosion resistant poor corrosion resistance. No magnetic attraction highly magnetic 316 410

111. VISUAL OBSERVATION TEST oCompare with standards oCOLOUR, oSURFACE, oSECTION AFTER FRACTURE etc.

112. HARDNESS TEST FILE HARDNESS TEST- WITH FILE USE SAMPLE AND COMPARE OBSERVE SCRATCHES ON SURFACE (eg: deep file scratches on structural steel, shallow on high carbon steel)

113. SURFACE REFLECTIVITY TEST A VISUAL TEST Compare ability to reflect light. (eg: Al & Mg.- Al more than Mg. Lead-tin: more tin- more reflectivity

114. WEIGHT PER VOLUME TEST Small sample in a graduated container Wt of metal/volume of water displaced Compare with known samples

115. CHEMICAL REACTION TEST  Test reaction with certain acids –simple / complex  METALS HAND BOOK, VOL 11. by American Society for Metals Eg: carbon content of carbon steel, test for Mn,

116. SPARK TEST To separate alloys containing known alloying elements Eg: MS, carbon tool steel, Mn, S, Ni content steels etc. Manganese Sulphur Nickel

117. REFER DATA BOOK FOR STANDARDS- SYMBOLS FOR DIFFERENT CLASSES UNIFIED NUMBERING SYSTEMS FOR METALS AND ALLOYS- SAE 1975