1、 FORD LABORATORY TEST METHOD EU-BO 054-01 Date Action Revisions 2001 03 28 Revi sed Editorial no technical change A. Cockman 1994 02 28 Printed copies are uncontrolled Page 1 of 3 Copyright 2001, Ford Global Technologies, Inc. INDENTATION HARDNESS TEST FOR PLASTICS Application This procedure is used
2、 to determine the ball indentation hardness values of plastics, integral foam and hard rubber. Scope The ball indentation hardness is the quotient of the major load and the area of indentation produced by a 5 or 10 mm diameter ball after the major load has been applied for the specified time (10 and
3、 60 seconds). Apparatus Required Ball Indentation Hardness Tester With preload of 2.94 N (0.3 kgf) 9.81 N (1.0 kgf) With major load of 49.05 N (5.0 kgf) 132.44 N (13.5 kgf) 358.07 N (36.5 kgf) 961.38 N (98.0 kgf) Note: Steel Ball: Hardened and polished steel ball with a Vickers hardness 7.85 kN/mm2
4、(800 kgf/mm2 ). The ball shall not exhibit any deformation or evidence of damage either before or after test. Measuring Scale: Scale value of the measuring equipment for the depth of penetration is 0.005 mm. Source: T. C. Howden & Co. Ltd. Althorpe Street Lemington Spar Warwickshire Stop Watch FORD
5、LABORATORY TEST METHOD EU-BO 054-01 Page 2 of 3 Copyright 2001, Ford Global Technologies, Inc. Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/- 2 C and 50 +/- 5 % relative humidity for not less than 24 h prior to
6、 testing and tested under the same conditions unless otherwise specified. Procedure 1. Place the test specimen perfectly flat on the support. Its test surface shall be at right angles to the direction of the applied load. Gradually apply the preload and set the dial gauge to zero. 2. Apply the major
7、 load evenly over 2 seconds. The major load is chosen so that the indentation depth is between 0.15 and 0.35 mm. 3. 10 seconds and 60 seconds after the major load has been applied, the depth of indentation is measured under load. Note: If the values for the indentation depth for individual test spec
8、imens or homogeneous series of specimens lie outside the specified range, so that changing to another major load would be necessary, then the major load to be applied is that for which the average value of the indentation depth after 60 seconds lies within the specified range. The number of test res
9、ults lying outside the specified indentation depth range shall then be stated in the test report. The test shall be carried out avoiding buckling of the edges or tearing of the test specimen. If several tests ar carried out on one test specimen the distance between the centres of any two adjacent in
10、dentations shall be at least 5 mm. The test surface and the bearing surface of the 4 mm thick test specimen shall be smooth, flat and parallel. If these conditions cannot be fulfilled, the deviations shall be stated in the test report. The test surface shall be large enough to permit the test to be
11、carried out as far away from the edge of the test specimen as possible to exclude the possibility of the test results being influenced by the edge region. No deformation shall be visible on the lower surface of the test specimen after completion of the test. The ball diameter (5 mm or 10 mm) will be
12、 chosen according to the specification requirement. Evaluation The ball indentation hardness is calculated as follows: For a 5 mm steel ball: H = 0.21 x F 0.21-hr +h 5pihr FORD LABORATORY TEST METHOD EU-BO 054-01 Page 3 of 3 Copyright 2001, Ford Global Technologies, Inc. For a 10 mm steel ball: H =
13、1 x F = 0.032 x F pi .D h h Where: F = Major load (N) D = Ball diameter (mm) H = Indentation depth in mm, allowance being madefor upward bending of the testing equipment. H = Hardness (N/mm2 ) hr = Reduced indentation depth in mm, this is 0.25 mm. Chemicals, materials, parts, and equipment referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities.
