1、 FORD LABORATORY TEST METHOD AQ 109-01 Date Action Revisions 2001 01 31 Revised Editorial no technical change A. Cockman 2000 04 25 Editorial no technical change A. Cockman 1992 06 03 Printed copies are uncontrolled Page 1 of 3 Copyright 2001, Ford Global Technologies, Inc. SILICATE TO HYDROXIDE RAT
2、IO - HYDROPHILIC SEALER FOR CONVERSION COATING Application This procedure determines the silicate to hydroxide ratio of the hydrophilic sealer for the conversion coating of aluminum. Apparatus Required Buret 50 mL; graduated to 0.1 mL Erlenmeyer Flask 250 mL Pipet Graduated Cylinder 100 mL Analytica
3、l Balance Precision 0.001 g; capacity 200 g Bottle(s) With stoppers, 1 L Materials Required Sodium Fluoride Reagent grade Isopropyl Alcohol Caution: Low flash point Deionized or Distilled Water 20 micromhos/cm at 25 C maximum conductivity (ASTM D 1125) FORD LABORATORY TEST METHOD AQ 109-01 Page 2 of
4、 3 Copyright 2001, Ford Global Technologies, Inc. Solutions Required Hydrochloric Acid 1 N (standardized to the nearest 0.001 N) Sodium Hydroxide 1 N (standardized to the nearest 0.001 N) Methyl Red Indicator Dissolve 0.1 g of methyl red in 100 mL of methyl alcohol Bromocresol Green Indicator Dissol
5、ve 0.1 g of bromocresol green in 50 mL of isopropyl alcohol and dilute to 100 mL with distilled water Methyl Orange Indicator Dissolve 0.1 g of methyl orange in 100 mL of distilled water Sodium Fluoride Slurry Refer to Procedure section Conditioning and Test Conditions All test values indicated here
6、in 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 testing and tested under the same conditions unless otherwise specified. Procedure 1. Combine 50.0 mL of Methyl Red solution and 50.0 mL of Bromocresol Green
7、. Note: It may be necessary to heat the solutions to assure that all the material is in solution prior to combining the solutions. 2. Prepare a neutralized sodium fluoride slurry by adding 100.0 g of sodium fluoride to 950 mL of distilled water in a 1 L bottle. Then add 2 to 3 mL of the Methyl Red/B
8、romocresol Green solution from step 1 and mix thoroughly. 3. Add 1 N hydrochloric acid to the sodium fluoride slurry from step 2 to obtain the gray/green color indicating neutrality. Note: The pH of this solution may drift and therefore must be checked and adjusted, if necessary, for neutrality befo
9、re each use. FORD LABORATORY TEST METHOD AQ 109-01 Page 3 of 3 Copyright 2001, Ford Global Technologies, Inc. 4. Pipet 25 mL of the sealer solution to be tested into a 250 mL Erlenmeyer flask and add one drop of Methyl Orange indicator. 5. Titrate the solution from step 4 with standardized 1 N hydro
10、chloric acid to a burned orange color endpoint. Record the titer volume (“C“) to the nearest 0.05 mL and retain this sample for use in step 6. 6. Add 75 mL of neutralized sodium fluoride from step 3 to the titrated solution of step 5. 7. Add 7 drops of the Methyl Red/Bromocresol Green indicator and
11、mix well. 8. Titrate the solution from step 7 with standardized 1 N hydrochloric acid to a burned orange color endpoint. Record the titer volume (“A“) to the nearest 0.05 mL. Note: A burned orange endpoint that drifts slowly to the gray indicates that additional sodium fluoride slurry is required. I
12、f needed, add 25 mL additional slurry and titrate as above to a permanent endpoint. 9. Back-titrate the sample from step 8 with standardized 1 N sodium hydroxide to a green endpoint. Record the titer volume (“B“) to the nearest 0.05 mL. Calculations Silicate/Hydroxide Ratio = 0.286 x ( (A x N HC1) -
13、 (B x N NaOH) ) C x N HCl A = mL of HCl from step 8 B = mL of NaOH from step 9 C = mL of HCl from step 5 N HCl = Standardized hydrochloric acid Normality to the nearest 0.001 N N NaOH = Standardized sodium hydroxide Normality to the nearest 0.001 N 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.
