1. Testing Of Materials


Published on

Published in: Business, Technology
  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

1. Testing Of Materials

  1. 1. I.) Testing of Materials <ul><li>A.) Need for Materials Testing </li></ul><ul><li>1.) Materials Research – developing new materials to meet a specific need. </li></ul><ul><li>2.) Product Design & Development </li></ul><ul><li>3.) Quality Control - test a sampling of product to ensure it meets specifications. </li></ul><ul><li>4.) Failure Analysis - Determine the cause of a product failure. </li></ul>
  2. 2. B.) Qualities of a Good Test <ul><li>1.) Standardized - Done the same way every time, by everyone who does it. A written procedure ensures this. </li></ul><ul><li>2.) Reliable - same results on repeated tests. </li></ul><ul><li>3.) Valid - measures exactly what you set out to measure. </li></ul><ul><li>4.) Objective - Same results regardless of who performs it. </li></ul>
  3. 3. B.) Qualities of a Good Test <ul><li>5.) Precise - measurements from repeated tests are the same </li></ul><ul><li>6.) Accurate - measurements are close to the target value. </li></ul><ul><li>7.) Little Inherent Error (vs Mistakes) - Inherent inaccuracies due to test set up and measurement devices </li></ul>
  4. 4. C.) Types of Mechanical Tests <ul><li>1.) Tension Test </li></ul><ul><li>2.) Compression Test </li></ul><ul><li>3.) Shear test </li></ul><ul><li>4.) Hardness Test </li></ul><ul><li>5.) Impact Test </li></ul><ul><li>6.) Fatigue Test </li></ul><ul><li>7). Flexure Test </li></ul><ul><li>8.) Creep Test </li></ul>
  5. 5. D.) Characteristic Mechanical Behavior of Materials <ul><li>1.) Brittle Failure </li></ul><ul><li>2.) Ductile Failure </li></ul><ul><li>3.) Elastic </li></ul><ul><li>4.) Plastic </li></ul><ul><li>5.) Resilient - absorb energy w/o permanent deformation </li></ul><ul><li>6.) Tough - absorb energy w/o fracture </li></ul>
  6. 6. E.) Nondestructive Tests <ul><li>1.) Liquid Penetrants </li></ul><ul><li>2.) Magnetic Particle </li></ul><ul><li>3.) Ultrasonic </li></ul><ul><li>4.) Radiography </li></ul><ul><li>5.) Eddy Current </li></ul>
  7. 7. F.) Measurements <ul><li>1.) Unit Conversion ( see p. 15) </li></ul><ul><ul><li>I.0 lb. = 0.225 Newtons (N) </li></ul></ul><ul><ul><li>1.0 lb = 453.6 grams (g) </li></ul></ul><ul><ul><li>1.0 in. = 25.4 mm </li></ul></ul><ul><ul><li>1 gallon = 231 cubic inches </li></ul></ul>
  8. 8. F.) Measurements <ul><li>2.) Significant Digits </li></ul>
  9. 9. G.) Physical Properties of Materials <ul><li>1.) Mechanical - see Mech. Tests </li></ul><ul><li>2.) Thermal </li></ul><ul><ul><li>a.) Melting Point </li></ul></ul><ul><ul><li>b.) Thermal Conductivity </li></ul></ul><ul><ul><li>c.) Specific Heat </li></ul></ul><ul><ul><li>d.) Coefficient of Thermal Expansion </li></ul></ul>
  10. 10. G.) Physical Properties of Materials <ul><li>3.) Electrical </li></ul><ul><ul><li>a.) Resistivity & Conductivity </li></ul></ul><ul><li>b.) Dielectric Strength </li></ul><ul><li>4.) Magnetic </li></ul><ul><li>5.) Optical </li></ul>
  11. 11. H.) Chemical Properties of Materials <ul><li>1.) Reactivity (corrosion resistance) </li></ul><ul><li>2.) Atomic Structure </li></ul><ul><li>3.) Crystalline Structure </li></ul>
  12. 12. I.) Weight-Volume Relationships <ul><li>1.) Density (  )- How much mass is in a given volume of material </li></ul><ul><li>Volume = Space occupied by the material (ft 3 , cm 3 ). </li></ul>
  13. 13. <ul><li>2.) UNIT WEIGHT (  </li></ul><ul><li>The Unit Weight of a material tells you the weight of a given volume of the material. </li></ul><ul><li>  W </li></ul><ul><li> V </li></ul><ul><li>  Unit Weight (lb/ft 3 ) </li></ul><ul><li> W= Weight of a body (lb) </li></ul><ul><li> V= Volume of a body (ft 3 ) </li></ul>
  14. 14. <ul><li>Example: A 2.0’ x 3.0’ x 4.0’ block of material weighs 11,760 lbs. Find the unit weight of the material. </li></ul><ul><li>W = 11,760 lb </li></ul><ul><li>V= 2.0’ x 3.0’ x 4.0’ = 24.0 ft 3 </li></ul><ul><li> = W = 11,760 lb = 490 lb = 490pcf </li></ul><ul><li> V 24.0 ft 3 ft 3 </li></ul>
  15. 15. <ul><li>Volumes of different shapes </li></ul><ul><li>a.) Cylinder = V CYL =  r 2 h </li></ul><ul><li>b.) Sphere = V SPH = 4  r 3 </li></ul><ul><li> 3 </li></ul>h r r
  16. 16. <ul><li>3. ) Specific Gravity (S.G.) - A comparison of the unit weight (or density) of a material to the unit weight (or density)of water. </li></ul>
  17. 17. J.) Additional Terms Regarding Test Quality <ul><li>1.) Significance - ability of a test to predict a material = s performance </li></ul><ul><ul><li>2.) Error - the difference between the observed value and the expected value. Caused by: </li></ul></ul><ul><ul><li>a.) Sample variability </li></ul></ul><ul><ul><li>b.) Instrument Sensitivity </li></ul></ul><ul><ul><li>c.) Instrument Calibration & Drift </li></ul></ul><ul><ul><li>d.) Environmental Factors - Temp. </li></ul></ul><ul><ul><li>e.) Measuring Method </li></ul></ul>