FORD-WSD-M8A18-A1-2003.pdf
ENGINEERING MATERIAL SPECIFICATION Date Action Revisions 2003 10 10 Revised Para 3.0 inserted; para 3.1, 3.8 and 4 deleted 1995 01 31 C10460360 Rev 3.2, 3.3.2, 3.3.3 Added A6 R. Cooper, P. Lee 1991 03 26 C10128525 Released N. Riley EAO, P. Lee NAAO Printed copies are uncontrolled Copyright © 2003, Ford Global Technologies, Inc. Page 1 of 3 BEARINGS, ALUMINUM-Sn STEEL BACKED WSD-M8A18-A1 BEARINGS, ALUMINUM-Sn-Si STEEL BACKED WSD-M8A18-A2 BEARINGS, ALUMINUM-Sn-Si STEEL BACKED WSD-M8A18-A3 BEARINGS, ALUMINUM-Sn-Si STEEL BACKED WSD-M8A18-A4 BEARINGS, ALUMINUM-Sn-Si STEEL BACKED WSD-M8A18-A5 BEARINGS, ALUMINUM-Sn STEEL BACKED WSD-M8A18-A6 1. SCOPE The materials defined by these specifications are Aluminum-Tin (A1 and A6) and Aluminum-Tin-Silicon (A2, A3, A4 and A5) bearing alloys bonded to a low carbon steel backing. 2. APPLICATION These specifications were released originally for material used in the manufacture of bearings and bushings for automotive applications. Uses include main and connecting rod bearings of medium load. 3. REQUIREMENTS 3.0 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to the Company's Standard Requirements For Production Materials (WSS-M99P1111-A). 3.2 CONSTRUCTION The functional layer shall be cast then processed into a wrought strip and roll-bonded onto a steel back. Bonding layers up to the following maximum thicknesses are allowed; nickel - 30 micrometers and/or aluminum - 75 micrometers thick on bearings up to 3 mm final wall thickness, and 125 micrometers for bearings greater than 3 mm. Functional Layer and backing thickness refer to the finished part and shall be stated on relevant Engineering Drawing. The functional layer shall include the bonding layer. 3.3 CHEMICAL COMPOSITION (weight %) 3.3.1 Steel Backing Low carbon steel (0.03 - 0.25% carbon). -,-,- ENGINEERING MATERIAL SPECIFICATION WSD-M8A18-A1/A6 Printed copies are uncontrolled Copyright © 2003, Ford Global Technologies, Inc. Page 2 of 3 3.3.2 Functional Layer A1 A2 A3 A4 A5 A6 Tin 17.5 22.5 8.0 12.0 10.0 14.0 5.5 7.0 10.0 14.0 7.0 13.0 Copper 0.7 1.3 0.7 1.3 0.7 2.3 0.7 1.3 0.9 1.3 0.2 1.6 Iron 0.7 max 0.7 max 0.7 max 0.7 max 0.7 max 0.7 max Silicon 0.7 max 3.0 5.0 3.0 5.0 1.0 2.0 3.0 5.0 Manganese 0.7 max 0.4 1.6 Total Others 0.5 max. 0.7 max 0.7 max 0.7 max 0.7 max 0.7 max Aluminum Balance Balance Balance Balance Balance Balance Nickel 0.7 1.3* 0.9 3.1 Silicon 0.7 max* * = Optional range The specific composition shall be selected from within one of the above ranges in order to meet component performance requirements and will form part of the approved Control Plan for each geometry and application. 3.3.3 Overlay/Surface Coating A tin flash with a maximum thickness of 3 micrometers can be applied for function to WSD-M8A18-A1 to A6 if required and shown on the drawing. 3.4 ADHESION The bond between the bearing layer and the steel backing must withstand the following test: A sharp chisel with a cutting width of 10 mm minimum and a cutting angle of 40 - 50° will be forced at an angle of 30 - 60° degrees between the bearing layer and the steel backing. The cutting motion of the chisel is in a direction which tends to pull the bearing layer away from the backing. The bearing layer must not flake or spall. 3.5 HARDNESS (The average of 5 determinations minimum on the functional surface) (ASTM E 92/ASTM E 10) A1 A2 A3 A4 A5 A6 HV min 32 35 55 35 35 40 or HB min 30 33 50 33 33 37 Note: Maximum hardness values will be part of the Control Plan and shall be stated on Engineering Drawing following sample manufacture. ENGINEERING MATERIAL SPECIFICATION WSD-M8A18-A1/A6 Printed copies are uncontrolled Copyright © 2003, Ford Global Technologies, Inc. Page 3 of 3 3.6 MICROSTRUCTURE The functional layer consists of a uniform distribution of tin particles in an aluminum rich solid solution matrix, and shall be bonded to the steel backing with no bonding or interface defects when viewed at 100 times magnification. The intermediate roll bonding layer, if used, shall be uniform and continuous along boundary length. WSD-M8A18-A2, A3 and A5 alloys shall additionally contain a uniform distribution of silicon particles with a maximum size of 25 micrometers in any direction. Any surface coating shall be uniform and continuous. 3.7 MECHANICAL PROPERTIES The mechanical properties of the steel backing shall be controlled directly or indirectly (e.g. hardness) as part of the control plan to ensure consistent installation and functional characteristics.
