1、FORD LABORATORY TEST METHOD BI 170-01 Date Action Revisions Rev. 0 2016 04 20 Released Matthew Corley, Irina Gruenwald, EU Controlled document at www.MATS Copyright 2016, Ford Global Technologies, LLC Page 1 of 4 Coating Thickness Measurement on Polymeric Substrates Using Microtome Sample Preparatio
2、n and Transmitted Light Optical Measurements Application This test method is used to determine the coating layer thickness on polymeric substrates. Individual layers of multilayer systems can be measured and photographed. Apparatus and Materials Required Microtome, capable of producing slices with t
3、hickness of 10 or less Transmitted Light Optical Microscope, with magnification minimum 400x and image capture software Glass slides and cover glass, standard microscope sample preparation Immersion oil Tweezers Scissors or Scalpel Test Panel Properties The location of the layer thickness measuremen
4、t on the part should be selected so that the location is representative of the part or section of the part. If required, additional locations should be identified and measured which show minimum and maximum layer thicknesses. Conditioning and Test Conditions For best results, samples should be teste
5、d at least 72 hours after production or painting. Samples are to be stored a minimum of 24 hours in 23 C and 50% relative humidity before testing. Materials which absorb water, such as polyamide 6, may require slightly different conditioning. Figure 1: Tools for preparing microtome samples FORD LABO
6、RATORY TEST METHOD BI 170-01 Copyright 2016, Ford Global Technologies, LLC Page 2 of 4 Test Procedure 1.) Preparation of Cross Sections The coated sample should be mounted onto the microtome sample holder such that the resulting cross-section slice is as close as possible to 90 to the coating surfac
7、e (See Figures 2 and 3) Slices are cut with the microtome blade. It is generally necessary to cut numerous slices until obtaining an optimal slice. Thinner slices are easier to evaluate with the microscope, but more difficult to cut. Approximately 10 thickness is recommended as starting point, but d
8、epending on material and color other thicknesses may be more suitable. The resulting slice should be flat or can be made flat by applying slight force. Handling of the slices is best done using tweezers. All wrinkles, deformed, torn or raised material, etc. should be removed with a scalpel or scisso
9、r Figure 2. Sample shown clamped in the microtome sample holder. Figure 3: Schematic of cutting of cross-section slice Microtome blade FORD LABORATORY TEST METHOD BI 170-01 Copyright 2016, Ford Global Technologies, LLC Page 3 of 4 Several drops of immersion oil are placed on the center of the glass
10、slide, the slice is placed flat on the oil drops and the cover glass is placed on top and gently put in place (See Figure 4). When viewing the slice under the microscope the entire width of the coating image should be simultaneously in focus at the magnification used for the measurement. 2.) Microsc
11、opy Procedure 400x magnification is recommended Microscope used in transmitted light mode (light source below specimen) Image analysis software cannot be described here as it is individual to the microscope and manufacturer. Software and microscope must be calibrated for the magnification settings s
12、o that accurate measurements can be made. Saved images must include a scale bar as shown in the bottom right corner of Figure 5. Measure the width of the image of the coating cross section at no less than five points distributed along a length of the microsection, and calculate the arithmetic mean o
13、f the measurements Report The test report shall include the following information: a) Date of painting. b) Identification of the test specimens (substrate, paint products used, color, part number). c) Sample conditioning information if different than described above. d) Location on the coated item a
14、t which the cross section was made (photos with arrows ideal). e) Set thickness of the microtome slice. f) The average thickness of the coating in micrometers at each point. Include all five individual points and the length of section over which the measurements were distributed. g) When requested,
15、photographic images of the layer cross-sections. Photos should include linear scale information. Figure 4: Slice on glass slide with oil and cover glass FORD LABORATORY TEST METHOD BI 170-01 Copyright 2016, Ford Global Technologies, LLC Page 4 of 4 Figure 5: cross section with 5 point along a microsection
