ASTM B406-96 pdf free.Standard Test Method for Transverse Rupture Strength of Cemented Carbides.
Specimens shall be ground to a surface finish of 15 uin.(0.381 um) rms maximum on four sides, and to the tolerancesspecified in Section 5.All grinding marks shall be parallel tothe length,0.750 in. (19.05 mm), axis. Opposite ground facesshall be parallel within 0.001 in. (0.0254 mm). The two facesthat are perpendicular to the length axis need not be ground.Careful grinding techniques should be used to prevent variousforms of surface cracking (flaws) that will degrade the measured strength. Long-established practice recommends the useof soft resin bonded diamond wheels, and copious quantities ofcoolant. For surface grinding, no pass shall exceed 0.0005 in.(0.0127 mm) in depth.
The four edges of the specimen representing the intersection of the ground faces shall be chamfered or honed to amaximum of 0.010 in. (0.25 mm) by 45 degrees.Any grindingmarks shall be parallel to the long axis of the specimen.6.3 Each specimen shall be measured to within 0.001 in.(0.02 mm) in both directions perpendicular to the length axis.Adjacent ground sides shall be at right angles to each otherwithin 2 degrees.
Each specimen shall be visually inspected after grind-ing. Any specimen on which cracks,chips,or obvious struc-tural defects appear on the ground surfaces shall be eliminatedfrom the test. Visually examine the cylinders and ball in the fixture forcracks，chips，deformation,，or misalignment and check themovable member for freedom of movement. Correct anydefects prior to use.
Place a properly prepared and measured specimen onthe fixture with the long axis perpendicular to the cylinders andwith the 0.250-in.(6.25-mm) face resting on the two cylinders.Then adjust the movable member so that the ball or uppercylinder contacts the specimen without substantial impact. If aball is used，place the specimen so that the ball touches themidpoint of the specimen width. Apply the load at a rate notexceeding 350 lbf/s (1.5 kN/s). Fracture should occur withinthe middle one third of the span between the supportingcylinders on the tension side of the specimen. Record thenumber of pounds required to cause fracture.ASTM B406 pdf download.