1、 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2018 Navistar, Inc. FEBRUARY 2018 Page 1 of 3 NAVISTAR, INC. Material, Parts, and Process Specifications
2、 (MPAPS) NUMBER: MPAPS BT-49 Former Designation: CEMS BT-49 TITLE: Determination Of Molybdenum Disulfide In Lubricants CURRENT REV No.: 1802 DATE: Feb. 2018 WRITTEN/EDITED BY: W. Cook APPROVED BY: R. Goluch SUPERSEDES: Rev. Aug 2009 PRINTED COPIES OF THIS DOCUMENT MUST BE VERIFIED FOR CURRENT REVISI
3、ON This specification may involve hazardous materials, equipment, and procedures. This specification does not purport to address all of the safety issues associated with its use. The user is responsible to consult appropriate safety and health practices and to determine the applicability of regulato
4、ry limits prior to use. 1.0 SCOPE This method covers a test procedure for determining molybdenum disulfide in lubricants by atomic absorption spectroscopy. 2.0 APPARATUS 2.1 Atomic-absorption Spectrophotometer, for use at 313.1 nm. 2.2 Molybdenum hollow-cathode lamp. 2.3 Pressure-reducing valves. 2.
5、4 Analytical balance with a sensitivity of 0.1 mg. 2.5 Hot plate. 2.6 Fume hood. 2.7 Beaker, 250 ml, Pyrex or equivalent. 2.8 Watch glass, 90 mm diameter, Pyrex or equivalent. 2.9 Volumetric flask, glass, 100 ml. 2.10 Volumetric flask, glass, 1000 ml. 2.11 Spatula, stainless steel, semi-micro. 2.12
6、Funnel, glass, 75 mm diameter, 150 mm stem. 2.13 Graduated cylinder, glass, 50 ml. 2.14 Pipette, glass, volumetric, TD, 10 and 20 ml. 3.0 MATERIALS 3.1 Oxidant: Nitrous Oxide, Commercial Grade. 3.2 Fuel: Acetylene, Commercial Grade. 3.3 Distilled water per ASTM D 1193, Type II. 3.4 Sulfuric acid, AC
7、S reagent grade, concentrated, H2SO4. 3.5 Nitric acid, ACS reagent grade, concentrated, HNO3. 3.6 Molybdenum disulfide, 98% MoS2 minimum assay. 3.7 Pipette, Pasteur, glass, 153 mm. 3.8 Material Blank for Standards preparation: Material having a composition similar to the analysis sample but containi
8、ng less than 0.001 mass percent molybdenum. NUMBER: MPAPS BT-49 TITLE Determination Of Molybdenum Disulfide In Lubricants REVISION: 1802 This document is restricted and may not be sent outside Navistar, Inc, or reproduced without permission from Corporate Technical Standards. Suppliers are required
9、to assume all patent liability. 2018 Navistar, Inc. FEBRUARY 2018 Page 2 of 3 4.0 PREPARATION OF STANDARDS 4.1 Weigh the following amounts of MoS2 and the Material Blank into three 250 ml beakers. Beaker M0S2, grams Material Blank, grams 1 0.10 0.001 4.90 2 0.15 0.001 4.85 3 0.20 0.001 4.80 4.2 Plac
10、e the beakers containing the standards in a fume hood and add 20 ml of H2SO4 to each beaker. Allow to stand at room temperature for ten minutes. CAUTION: With some samples, there may be an immediate reaction with the H2SO4. Let any reaction subside before performing Step 4.3. 4.3 Add 20 ml of HNO3 t
11、o each beaker, cover beakers with watch glasses and place samples on a cold hot plate. 4.4 Turn on hot plate and digest samples until the solution remains clear. Cautious periodical additions of 1 to 3 ml HNO3 with a glass pipette will be necessary until the digestion is complete. 4.5 Quantitatively
12、 transfer the contents of each beaker to individual 1000 ml volumetric flasks and dilute to the mark with distilled water. NOTE: Standards may be retained for up to three months for future use on similar materials. 5.0 PROCEDURE 5.1 Weigh 5 + 0.001 g of test sample into a 250 ml beaker. 5.2 Digest a
13、nd dilute sample as described under ”Preparation of Standards, Steps 4.2 thru 4.5. 5.3 Operate the atomic-absorption spectrophotometer per manufacturers instructions for use at 313.3 nm, using a nitrous oxide/acetylene flame. 5.4 Pipette 20 ml aliquots from the flasks in Step 5.2 to 100 ml volumetri
14、c flasks and dilute to the mark with distilled water and record absorbance, at 313.3 nm, of the standard and test sample dilutions using a Nitrous Oxide flame. NOTE: If the Spectrophotometer is equipped with a data processor, the concentration of MoS2 may be determined directly. See the manufacturer
15、s instructions for procedure. 6.0 CALCULATION 6.1 Plot a graph of mass percent M0S2 versus absorbency for the standards. Mass % MoS2 in standards: Mass % = wt. M0S2 x Purity of M0S2 x100 Wt. Material Blank + wt. M0S2 6.1.1 If the absorbency of the test sample does not fall on the calibration curve,
16、adjust aliquot and final dilution volume as per Step 5.4, to make absorbency fall on calibration curve. NUMBER: MPAPS BT-49 TITLE Determination Of Molybdenum Disulfide In Lubricants REVISION: 1802 This document is restricted and may not be sent outside Navistar, Inc, or reproduced without permission
17、 from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2018 Navistar, Inc. FEBRUARY 2018 Page 3 of 3 6.2 Plot the absorbency of the test sample on graph for the standards and determine mass percent MoS2 in sample from group. Mass % = MoS2 in sample = A 20100BC A
18、= Value, mass % MoS2, obtained from graph. B = Final volume to which sample is diluted, Step 5.4. . C = Aliquot of sample from Step 4.5 used in Step 5.4. . NOTE: Mass percent molybdenum in the sample may be calculated as follows: Mass % M0 in Sample = mass % Molybdenum disulfide (MoS2) in sample x 0.599 7.0 REPORT Mass percent molybdenum disulfide (MoS2) or molybdenum (Mo) to the nearest 0.005 mass percent. REVISION HISTORY Revision Level Change Approved by Date Approved 1802 Converted to MPAPS R. Goluch 2/13/2018
