1、 FORD LABORATORY TEST METHOD BQ 103-06 Date Action Revisions 2000 11 10 Revised Editorial no technical change A. Cockman 1999 01 20 Printed copies are uncontrolled Page 1 of 6 Copyright 2000, Ford Global Technologies, Inc. MEASUREMENT OF CRACK DENSITY OF MICRO-CRACKED OR PORE DENSITY OF MICRO-POROUS
2、 ELECTRODEPOSITED CHROMIUM Application This procedure is used to determine the crack density of micro - cracked or the pore density of micro - porous electroplated deposits. Apparatus Required Anode A copper anode should be used. Current Source A D -C current source capable of supplying a current de
3、nsity of 1.6 A/dm to the surface being evaluated. A satisfactory current source is available from Hewlett Packard. Ammeter An ammet er is connected to the circuit to determine the current. The measuring range of the ammeter used will depend upon the surface area to be plated. Plating Tank (for Metho
4、d A) The tank should be of sufficient size to completely immerse the item to be tested in the plating solution. The tank should be constructed in such a manner that any surfaces coming into contact with the plating solution should be non -reactive with the solution. A VWR #60462 series or equivalent
5、 tank of the proper size would be satisfa ctory. Source: VWR Scientific Retaining Ring (for Method B) If necessary, a retaining ring, constructed of a non - reactive material may be used to support the viscous electrolyte. This retainer may be customer made to conform to a particular part configu ra
6、tion in the area to be tested. Metallurgical Microscope A metallurgical microscope is to be used in determining either crack density or pore density. A Meiji binocular, 4X, 10X, 20X, 40X, objective 10 eye pieces, 4x4 mechanical stage, Model ML7000 or e quivalent is satisfactory. For determining crac
7、k density a cross line disc Leica #31 - 16 - 30 or equivalent is required. For determining pore density a Howard Disc Leica #31 - 16 - 15 or equivalent is required; 25 mm long with 1.0, 0.1 and 0.02 mm divisions. Source: I.Miller Precision Optical Instrument Inc. 35 N. Second St. Philadelphia, PA 19
8、106 Tel : (215)925 - 2285 Fax: (215)925 - 8374 FORD LABORATORY TEST METHOD BQ 103-06 Page 2 of 6 Copyright 2000, Ford Global Technologies, Inc. Materials Required Tri Sodium Phosphate M - 1048 Sulfuric Acid 5% by volume H 2 SO 4 ; Reagent grade. Caution: Corrosive Copper Sulfate CuSO 4 ; Reagent gra
9、de. Agar-Agar Copper Fluoborate Cu(BF 4 ) 2 ; Reagent grade. Distilled or Deionized Water 10 ppm dissolved solids maximum (ASTM D 1880). Solutions Required Cleaning Solution 1. 22 - 30 g/L of Tri Sodium Phosphate (M - 1048). 2. D eionized water baths. 3. A bath of 5% by volume sulfuric acid in deion
10、ized water. Method A Copper Sulfate (CuSO 4 5H 2 0) 210 - 240 g/L Sulfuric Acid (H 2 SO 4 ) 45 - 60 g/L NOTE: Always add acid to the water Method B Solution for use with retaining rin g: Agar - Agar 50 - 70g Copper Fluoborate (Cu(BF 4 ) 2 ) 250 mL H 2 O (distilled or deionized) 750 mL FORD LABORATOR
11、Y TEST METHOD BQ 103-06 Page 3 of 6 Copyright 2000, Ford Global Technologies, Inc. Solution for use without retaining ring: Agar - Agar 100 - 150 g Copper Fluoborate (Cu(BF 4 ) 2 ) 250 mL H 2 0 (distilled or deioni zed) 750 mL Masking Material Hardman Extra Fast Setting Epoxy, or X - P 2000 masking
12、material, or equivalent Source: Harcos Chemicals Inc. A&M Industrial 600 Cortland St. 2565 Trotter Drive Belleville, NJ 07109 Alpharetta, GA 30004 Tel: (201) 751 - 3000 Tel : (800) 446 - 4750 Fax: (770)772 - 6403 Conditioning and Test Conditions All test values indicated herein are based on material
13、 conditioned in a controlled atmosphere of 23 +/ - 2 C and 50 +/ - 5% humidity for not less than 24 h prior to testing and tested under the same conditions unless otherwise specified. Procedure Method A The specimen to be tested should have been recently chromium plated to ensure reliability of resu
14、lts. 1. Mask all cut edges and, if practicable, all su rfaces not chromium plated. The conductor carrying current to the specimen during plating should also be masked at and below solution level, except where it makes contact with the specimen. 2. Soak the masked specimen in the hot alkaline cleaner
15、 at a tem perature of 70 - 85 C. 3. Rinse in hot deionized water at a temperature of 80 - 90 C. 4. Dip in the 5% sulfuric acid solution (in and out). 5. Rinse in hot deionized water bath (2nd rinse) at a temperature of 80 - 90 C. 6. Using “live“ entry, plate the specimen (part is cathodic) at 0.3 am
16、p/dm of immersed plated surface for 15 minutes. 7. Rinse the specimen carefully in cold (approximately 5 - 15 C) and then in hot tap water (approximately 45 - 65 C) and allow to dry. DO NOT WIPE, RUB OR TOUCH TH E AREAS ON WHICH PORES ARE TO BE COUNTED. (The copper nodules which are deposited at the
17、 discontinuity or crack sites are not firmly attached, and any physical contact after copper plating may remove some of these nodules and cause serious errors in measu rement.) FORD LABORATORY TEST METHOD BQ 103-06 Page 4 of 6 Copyright 2000, Ford Global Technologies, Inc. Method B 1. Clean the area
18、 to be tested as in Steps 2 - 5 of Method A. 2. Place the retaining ring and electrolyte - gel (or electrolyte - gel only if self - supporting gel is employed) on the area to be tested. 3. Place the copper anode, such as a piece of copper foil, within the gel. 4. Pass a current of 1.6 dm 2 of covere
19、d surface for 15 minutes through the part. (The test part becomes the cathode.) 5. Rinse and discard the gel carefully from the test part. The part should be treated as in Ste p 7, Method A. A. Grid Method - Visual, Using a Metallurgical Microscope 1. In a suitable 10X microscope eyepiece, insert a
20、micrometer disc (Howard Micrometer Disc, Leica #31 - 16 -15) containing ruled grid squares. The eyepiece should be capable of accom modating the disc in the proper focal plan so that the grid and the image of the plated surface are clear and sharp. 2. Using a standard metallurgical microscope with t
21、he above prepared eyepiece and a 10X objective, to give a total magnification of approx imately 100X, calibrate the ruled grid on the micrometer disc against a stage micrometer ruled in 0.25 and 0.025 mm intervals to determine the area covered by the ruled grid. 3. Determine the disc magnification f
22、actor by taking the reciprocal of the above calculated area. 4. Count the number of copper nodules in the area covered by the ruled grid on the micrometer disc. 5. Assuming that a visible copper nodule is deposited at each pore site, the calculated number of pores per cm is the product of the nu mbe
23、r of nodules counted in the area covered by the ruled grid on the micrometer disc and the micrometer disc magnification factor determined in Step 3 above. B. Photomicrographic Method Using a Metallurgical Microscope 1. To a standard metallurgical micr oscope containing a 10X objective, attach suitab
24、le photomicrographic equipment containing an eyepiece, the combination of which will result in a magnification of about 100X at the film plane and a film area of at least 60 x 90 mm. Because of variations in such types of photomicrographic equipment, it should be calibrated against a stage micromete
25、r. 2. Photograph the desired representative areas and obtain positive prints showing the copper nodules. FORD LABORATORY TEST METHOD BQ 103-06 Page 5 of 6 Copyright 2000, Ford Global Technologies, Inc. 3. Count the number of visible nodules in the photograp hic print in a measured 9 cm by laying or
26、placing a transparent ruled 9 cm grid or other suitable measuring device containing a measured 9 cm open area on the photographic print. 4. Calculate the actual number of nodules per cm on the surface examine d by multiplying the number of nodules in the measured 9 cm print by the square of the actu
27、al magnification value of the print. C. Photomicrographic Method Using Inverted Microscopic Equipment such as a Metallograph 1. Place the part or panel on the ins trument stage, supported in such a way that the areas to be photographed do not touch or rest on the stage. 2. Using a 10X objective and
28、a low power eyepiece, such as 5X, adjust the bellows on the camera to give a magnification of 100X at the film plane a s determined by calibration against a stage micrometer. 3. Photograph, count and calculate the assumed pores per cm in the same way as in Method B. General Notes 1. Any standard met
29、allurgical microscope can be used in the Grid or Photomicrographic met hods since calibration against a stage micrometer is required in all cases. 2. For the grid method of measurement (Method A), any type of micrometer disc containing a number of squares in a ruled grid, such as the Bausch and Lomb
30、 Howard Disc, appears to b e suitable. 3. One type of portable photomicrographic equipment adaptable to use on standard metallurgical microscopes (Method B), is the Polaroid Microcam photomicrographic apparatus available at I.Miller Precision Optical Instrument Inc. 4. When using a photomicrographic
31、 method (Methods B and C), an optical measuring device consisting of a metal frame with a 9 cm opening in the base and a magnifying lens attached to the top of the frame, known as a “linen tester“, appears to be satisfactory for countin g nodules visible in the photographic print. The attachment of
32、two fine cross wires in the 9 cm opening of the linen tester is helpful in counting very high porosity values. Procedures for Counting Cracks (For Micro-Cracked Electroplated Deposits) A. Linear Method - Visual, Using a Metallurgical Microscope 1. In a suitable 10X microscope eyepiece, insert a micr
33、ometer disc containing, preferable a single ruled line (cross line disc Leica #31 - 16 - 30). The eyepiece should be capable of accommodating the disc in the proper focal plane so that the grid and the image of the plated surface are clear and sharp. FORD LABORATORY TEST METHOD BQ 103-06 Page 6 of 6
34、 Copyright 2000, Ford Global Technologies, Inc. 2. Using a standard metallurgical microscope with the above prepared eyepiece and a 10X objective, to give a total magnification of approximately 100 X, calibrate the ruled line on the micrometer disc against a stage micrometer ruled in 0.25 and 0.025
35、mm divisions to determine the length covered by the ruled grid. 3. Determine the disc magnification factor by taking the reciprocal of the above calculat ed length. 4. Count the number of cracks intersected by the ruled line on the micrometer disc. 5. Assuming that copper is deposited in each crack,
36、 the calculated number of cracks per 25 mm is the product of the number of cracks counted in the length cove red by the ruled line on the micrometer disc and the micrometre disc magnification factor determined in Step 3 above. B. Photomicrographic Method Using a Metallurgical Microscope 1. To a stan
37、dard metallurgical microscope containing a 10X objective, attac h suitable photomicrographic equipment containing an eyepiece, the combination of which will result in a magnification of about 100X at the film plane and a film area of at least 60 x 90 mm. Because of variations in such types of photom
38、icrographic equipme nt, it should be calibrated against a stage micrometer. 2. Photograph the desired representative areas and obtain positive prints showing the cracks. 3. Count the number of visible cracks in the photographic print intersected by a line 25 mm long by layi ng or placing a transpare
39、nt ruled 25 mm line or other suitable measuring device containing a measured 25 mm line or on the photographic print. 4. Calculate the actual number of cracks per mm on the surface examined by multiplying the number of cracks inte resected by the measured line on the photographic print by the actual
40、 magnification value of the print. C. Photomicrographic Method Using Inverted Microscopic Equipment such as a Metallograph 1. Place the part of panel on the instrument stage, supported in such a way that the areas to be photographed do not touch or rest on the stage. 2. Using a 10X objective and a l
41、ow power eyepiece, such as 5X, adjust the bellows on the camera to give a magnification of 100X at the film plane as determined by calibrat ion against a stage micrometer. 3. Photograph, count, and calculate the assumed cracks per cm in the same way as in Method B above. * See “General Notes“ for “Procedure for Counting Pores“. 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.
