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Material Testing

by Manoj Kumar Rout
Type: PracticalInstitute: Biju Patnaik University of Technology Specialization: Mechanical EngineeringDownloads: 2Views: 45Uploaded: 7 months agoAdd to Favourite

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Manoj Kumar Rout
Manoj Kumar Rout
LABORATARY MANUAL MATERIAL TESTING LAB DEPARTMENT OF MECHANICAL ENGINEERING
CHARPY TEST AIM OF THE EXPERIMENT:To find out the impact test strength of the supplied Specimen by charpy test. APPARTUS REQUIRED:1. 2. 3. Universal pendulum impact testing Machine Supplied Specimen Slide Calipers THEORY:Impact strength can be defined as the resistance of the material to fracture under impact loading i.e. under quickly applied dynamic load. The notch impact strength ‘I’ is calculated by the following relation:I = K/A Where I = Impact strength in joule/m2 K = Impact energy absorbed on rupture in joule A = Area of cross section. PROCEDURE:1. For conducting charpy test, charpy striker was to be firmly secured to the bottom of the hammer with the help of charpy piece. 2. The latching tube to be firmly secured to the bracket fitted at the top of the column with the help of socket head screws. 3. Before proceeding to the actual test , the test for determining the frictional loss in the machine was to be calculated. 4. Reading pointer was adjusted with the pointer carrier to 30 Kgm/300J dial reading when the pendulum was hanging free vertical for this use socket head screw of carrier. 5. Now hammer was released by operating livers, the pointer will now indicate the energy loss due to friction. 6. For this reading, confirm that the friction loss was not exceeding 0.05% of the initial potential. 7. The specimen was placed on the specimen support touching the end stop. the specimen should be placed in such a way that the notch was averted to the direction of impact of the pendulum. For correct centering of the specimen the end stop was provided.
8. After the pendulum shows position of the reading pointers on the dial, the reading was noted. 9. Then the broken piece from the machine was removed and reading pointers was brought to 30kgm/300J dial. OBSERVATION:Technical Data:1. 2. 3. 4. 5. Angle of drop---------------------------------------------------------------1200 Maximum impact-----------------------------------------------------------300J Effecting weight of pendulum---------------------------------------------21kg Striking velocity-------------------------------------------------------------5.3485m/s Distance from axis of rotation of pendulum to center of specimen---815mm TABULATION:No of Length of side Length of Area observat below notch in notch in mm below ion mm notch mm2 Impact Impact strength in strength I in Joule(K) = K/A in J/mm2 CALCULATION:K =? A =? Then I = K/A PRECUTION:1. 2. 3. 4. Machine should be handed carefully Brakes should be applied at exact time and place. Tightening of specimen was properly done. Do not allow any one to stand in front of the swinging pendulum. CONCLUSION:The impact strength of the specimen by charpy test was found to be------J/mm2
IZOD TEST AIM OF THE EXPERIMENT:To find out the impact strength of the supplied specimen by izod test. APPARETUS REQUIRED:1. Impact testing machine 2. Supplied specimen 3. Venire THEORY:Impact strength can be defined as the resistance of the material to fracture under impact loading i.e. under quickly applied dynamic load. The notch impact strength ‘I’ is calculated by the following relation:I = K/A Where I = Impact strength in Joule/m2 K = Impact energy absorbed on rupture in Joule A = Area of cross section PROCEDURE:1. For Izod test a proper striker was ensured firmly. 2. The latching tube for Izod test was firmly screwed to the bearing at the side of the column. 3. The steel wire coming from the latch is carried through latching tube and was fastened to the interior of the release lever. 4. For Izod test was firmly secured in specimen support with the help of the clamping screw & Allen key supplied. 5. Care was taken that the notch in the specimen faces the pendulum strikes 6. Then the lever was operated after conforming that there was no pressure in the range of swinging. 7. Then the pendulum was set free and smashes the specimen. 8. Operating the pendulum brake carefully retarded the swinging pendulum. 9. The off position of the reading pointer on the dial was read and value was noted.

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