BS EN 843-7:2010 pdf free.Advanced technical ceramics Mechanical properties of monolithic ceramics at room temperature C-ring tests.
BS EN 843-7 A mechanical testing machine capable of applying a force to the test jig at a constant displacement rate or at constant loading rate. The testing machine shall be equipped for recording the load applied to the test jig at any point in time. The accuracy and calibration of the testing machine shall be in accordance with EN Iso 7500-1:2004, Grade 1 (1 % of indicated load).
For Method A, the testing machine shall be equipped with hard flat anvils with faces either fixed parallel to within 0,05 mm over the area to be used for testing, or self- aligning during testing.For Method B, the testing machine shall be equipped with a device for permitting two hard steel rollers to be inserted through the ring and supported at each end by yokes connected to the testing machine which permit a tensile force to be applied. Universal joints shall be incorporated into the load train to permit alignment and to minimise stress concentrations towards one face or other of the ring.
Any suitable altemative arrangement may be used in which the load can be applied in compression mode using a lever system containing the loading rollers.Precautions shall be taken to avoid flying fragments from the test-piece during fracture.
Thin, compliant materials such as cardboard, metal foil or rubber sheet, to be placed between the test piece and the compression anvils (Method A) or steel rollers (Method B).
Test pieces or test material shall be selected in accordance with the guidelines in EN 1006. If the test rings are to be cut from tube stock, select stock which is acceptably round and straight.Make an axial cut through the wall of the ring using a diamond saw. For Method A the slot width shall be sufficiently large that the sides of the slot do not close during the test before failure of the test-piece. For thickwalled test-pieces, a slot of 1 mm to 2 mm is adequate, but for thinner walled test-pieces, the slot shall be rather wider.BS EN 843-7 pdf download.