1、 ENGINEERING MATERIAL SPECIFICATIONDate Action Revisions 2009 01 21 Activated C. Mracna, FNA Printed copies are uncontrolled Copyright 2009, Ford Global Technologies, LLC Page 1 of 5 PLATING, CHROMIUM, DECORATIVE EXTERIOR, ALUMINUM WSS-M1P73-C1 LEVEL 1 CORROSION PLATING, CHROMIUM, DECORATIVE EXTERIO
2、R, ALUMINUM WSS-M1P73-C2 LEVEL 2 CORROSION 1. SCOPE This specification defines performance requirements for exterior chromium plating systems on aluminum substrates. 2. APPLICATION This specification was released originally to define a decorative and/or protective metallic finish for aluminum alloy
3、road wheels. 3. REQUIREMENTS All part testing requirements apply to those areas of the part identified as a significant surface per sec 4.1 unless otherwise specified on the engineering drawing. 3.1 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to
4、the Companys Standard Requirements For Production Materials (WSS-M99P1111-A). 3.2 APPEARANCE 3.2.1 Buffing of Plating Because of the potential adverse effect on corrosion resistance, buffing of final chromium plating on exterior parts is not permitted. Brushing or other approved mechanical treatment
5、 on nickel or copper coatings are permitted provided that minimum plating thickness requirements are met after treatment. 3.3 PLATING ADHESION (ASTM B 571) Adhesion of the electroplate to the base metal and between layers of plating must conform to the requirements of the following test methods per
6、ASTM B 571 unless otherwise indicated: 3.3.1 Bend Tests No peeling, flaking, or lift-off of the electroplate from the substrate or between layers of the electroplate is permitted. ENGINEERING MATERIAL SPECIFICATIONWSB-M1P73-C1/C2 Printed copies are uncontrolled Copyright 2009, Ford Global Technologi
7、es, LLC Page 2 of 5 3.3.2 Grind-Saw Test No lifting or peeling of the electroplate from the substrate or between layers of the electroplate is permitted. 3.3.3 Scribe-Grid Test 5% Plating Removal Lightly hand sand plated surface (10 double rubs, moderate pressure) with P600 paper until dull, before
8、scribe operation. Scribe eight lines in a rectangular grid in 0.5 cm increments. Use 3M No. 898 pressure sensitive tape. No peeling, flaking, or lift-off of the electroplate from the substrate or between layers of the electroplate is permitted. 3.4 DUCTILITY (ASTM B 490) Although this is considered
9、a portion of the process control and not a requirement of part performance, the ductility of the electrodeposit on a finished part is considered acceptable when foils plated in the individual nickel baths meet or exceed the following values: Semi-bright Nickel 80% Bright Nickel 20% 3.5 PLATING THICK
10、NESS (ASTM B 487, ASTM B 556, ASTM B504) It is the suppliers responsibility to identify the plating thickness distribution for each unique part design and rack design by mapping the plating racks and plated parts and to employ any special processing techniques, e.g., the use of auxiliary anodes and/
11、or shields, reducing the number of parts per rack etc., which may be required to consistently meet the specified minimum plating thicknesses on all significant surfaces. The optical measurement of copper and nickel deposits on significant surfaces shall be considered the standard thickness test meth
12、od (ASTM B 487). The chromium plate thickness on significant surfaces shall be checked by the spot test as described in ASTM B 556 or by the electronic deplating test, ASTM B504, Determination of Thickness of Chromium Plate. In case of dispute, ASTM B504 shall be the umpire method. The plating thick
13、ness requirements identified below represent minimum values in micrometers and apply to all areas of significant surfaces. Thickness Copper 15 Semi-bright Nickel (a) 30 Bright Nickel (b) plus 10 Special Nickel (c) or Low Gloss Nickel (d) Total Nickel (e) 40 Microporous Chromium (f) 0.18 ENGINEERING
14、MATERIAL SPECIFICATIONWSB-M1P73-C1/C2 Printed copies are uncontrolled Copyright 2009, Ford Global Technologies, LLC Page 3 of 5 3.6 MICROPOROSITY, min 10 000 pores/cm2(FLTM BQ 103-06) 3.7 THERMAL CYCLE AND CASS TEST (ASTM B 368) There shall be no evidence of plating failure on significant surfaces d
15、ue to corrosion or loss of adhesion to the substrate after completing six cycles consisting of the following 3.7.1 Requirements for Testing . 121 +/- 2 C for 2 h . 23 +/- 2 C for 1 h . -35 +/- 2 C for 2 h . 23 +/- 2 C for 1 h . 16 h Cass test (ASTM B 368) Note: Parts shall be rinsed with demineraliz
16、ed water only, after each Cass test cycle. Scrubbing, abrasive cleaning or polishing is not permitted. Parts are then examined for corrosion defects. 3.7.2 Plating and Corrosion Defects 3.7.2.1 Cracks and Crazing Cracks and crazing of the plating are caused by expansion and/or contraction due to tem
17、perature change. Cracks or crazing exceeding 6 mm in length observed on significant surfaces shall be considered failure of the part. 3.7.2.2 Blistering and Corrosion Blisters defined as “pop-ups“ can be caused by improper plating or be the result of corrosion. Failure is noted when: Any site (pit a
18、nd/or hole) larger than 1.5 mm on any significant surface (not including run down stain) shall be considered failure of the part. More than 1% base metal corrosion or blisters (grid method) of the entire significant surface area, shall be considered a failure of the part. 8% or more blisters or base
19、 metal corrosion in a grid section containing 100, 6.0 x 6.0 mm spaces (10 x 10 spaces) placed anywhere on the significant surface (local corrosion) shall be considered failure of the part. ENGINEERING MATERIAL SPECIFICATIONWSB-M1P73-C1/C2 Printed copies are uncontrolled Copyright 2009, Ford Global
20、Technologies, LLC Page 4 of 5 3.8 ACCELERATED CORROSION TEST (CETP 00.00-L-467 contact Ford Wheels Engineering to determine Corrosion Level requirement) WSS-M1P73-C1 12 weeks (Level 1) WSS-M1P73-C2 10 weeks (Level 2) At test termination, wheel must have an acceptable as-installed appearance based on
21、 a jury evaluation of at least two people, one person from Ford Wheels Engineering, and the other from either Ford Wheels or Materials Engineering. Additionally, the wheel appearance must meet the minimum appearance requirements as defined in the corrosion evaluation photo guides located in the Glob
22、al Engineering Standard, 18-0040, Reference 1. 3.9 SIMULTANEOUS THICKNESS AND ELECTROCHEMICAL POTENTIAL TEST (S.T.E.P.) (FLTM BQ 104-05) 3.9.1 The semi-bright nickel layer must be more noble (cathodic) than the bright nickel layer by a minimum of 100 millivolts. 3.9.2 If a microporous top nickel lay
23、er is used, it shall be equal to or more noble than the bright nickel layer potential. However, the potential of the microporous nickel shall not be more than 20 mV noble (cathodic) to the bright nickel layer. 3.10 SECONDARY SURFACES (WSS-M1P122-C1) To achieve an acceptable aesthetic appearance, the
24、 brake and tire sides of the rim of chrome plated wheels are often times painted. These paints are required to meet the requirements of painted aluminum wheels per WSS-M2P122-C1, except accelerated weathering hours 1500. 4. GENERAL INFORMATION The information given below is provided for clarificatio
25、n and assistance in meeting the requirements of this specification. 4.1 SIGNIFICANT SURFACES Unless otherwise specified on the engineering drawing, significant surfaces are defined as those surfaces of the finished part that: . are directly visible and/or visible by reflection when the finished part
26、 is assembled in car position. . can be the source of corrosion products directly visible or visible by reflection. 4.2 PLATING THICKNESS REFERENCE (a) The sulfur content in the semi-bright nickel bath shall be less than 0.005% (weight %). The sulfur content is specified to indicate the type of nick
27、el plating solution that is to be used and may be measured per the test procedures identified in ASTM B 456. In-process testing to determine conformance to the sulfur content requirement is essential to establish and maintain process capability and control. ENGINEERING MATERIAL SPECIFICATIONWSB-M1P7
28、3-C1/C2 Printed copies are uncontrolled Copyright 2009, Ford Global Technologies, LLC Page 5 of 5 (b) The sulfur content in the bright nickel bath shall be greater than 0.04% (weight %). The sulfur content is specified to indicate the type of nickel plating solution that is to be used and may be mea
29、sured per the test procedures identified in ASTM B 456. In-process testing to determine conformance to the sulfur content requirement is essential to establish and maintain process capability and control. (c) If a special nickel is employed to produce discontinuities in the chromium deposit, the thi
30、ckness of the special nickel shall be added to the measurement of the bright nickel deposit to meet the combined bright nickel plus special nickel minimum thickness requirement. If a special nickel layer is not used, the minimum thickness requirement applies only to the bright nickel deposit. (d) Lo
31、w gloss nickel may be produced by one of the following methods: 1) Co-deposit containing inorganic particles insoluble in the plating bath. 2) Soluble addition agents co-deposited with the nickel. 3) Mechanical treatment of a bright nickel deposit, e.g., brushing or bead blasting. When low gloss nic
32、kel is specified, special nickel need not be applied. (e) The semi-bright nickel thickness shall be greater than or equal to 60% of the total nickel thickness. The bright nickel thickness shall be less than or equal to 40% of the total nickel thickness. (f) Microporous chromium plating systems accep
33、table under this specification are defined as those being capable of producing microporosity in conformance with section 3.6. 4.3 APPROVAL TEST RECOMMENDATIONS FOR DESIGN AND IN-PROCESS VALIDATION Specified Requirement DV Sample Size PV Sample Size In-Process 3.3 Plating Adhesion 3 3 1/Shift 3.4 Duc
34、tility 1 n/a n/a 3.5 Plating Thickness 3 n/a 1/Shift 3.6 Microporosity 1 n/a n/a 3.7 Thermal Cycle / CASS Testing 3 3 1/Month 3.8 Accelerated Corrosion 1 n/a n/a 3.9 S.T.E.P. Test 1 1 1/Month 3.10 Secondary Surfaces 1 n/a n/a 4.4 SUMMARY OF REVISIONS 2009 01 21 - Completely revised an updated WSB-M1P73-B/B2 o Removed Feasibility section o Removed Pretreatment section o Added Scribe Test (sec. 3.3.) o Changed thermal cycle requirements from 3 to 6 cycles o Revised Accelerated Corrosion Test to new CETP method o Added Secondary Surfaces requirements (sec. 3.10)
