1、 ENGINEERING MATERIAL SPECIFICATIONDate Action Revisions 2003 10 10 Revised Para 3.0 inserted; para 3.1, 3.8 and 4 deleted 1993 03 04 C10283346 Released R. A.Cooper, EAO; A. N. Novakovic, NAAO Printed copies are uncontrolled Copyright 2003, Ford Global Technologies, Inc. Page 1 of 3 BEARINGS - LEAD
2、BRONZE STEEL BACKED WSD-M8A20-A1 BEARINGS - LEAD BRONZE STEEL BACKED WSD-M8A20-A2 BEARINGS - LEAD BRONZE STEEL BACKED WSD-M8A20-A3 BEARINGS - LEAD BRONZE STEEL BACKED WSD-M8A20-A4 1. SCOPE The materials defined by these specifications are medium leaded Bronze bearing alloys bonded to a low carbon st
3、eel backing. 2. APPLICATION These specifications were released originally for material used in the manufacture of bearings and bushings for automotive applications. Uses range to include high loaded bushings and medium loaded main bearings. 3. REQUIREMENTS 3.0 STANDARD REQUIREMENTS FOR PRODUCTION MA
4、TERIALS Material suppliers and part producers must conform to the Companys Standard Requirements For Production Materials (WSS-M99P1111-A). 3.2 CONSTRUCTION The functional layer shall be either cast or an alloyed powder sinter bonded onto the steel backing and processed to final condition. Nickel in
5、terlayers between overlay and functional layer, and Copper or Brass interlayers between the functional layer and backing are permitted. Layer and backing thicknesses as stated on relevant Engineering drawing. 3.3 CHEMICAL COMPOSITION (weight %) 3.3.1 Steel Backing Cold rolled low carbon steel (0.03
6、- 0.25% carbon). ENGINEERING MATERIAL SPECIFICATIONWSD-M8A20-A1/A4Printed copies are uncontrolled Copyright 2003, Ford Global Technologies, Inc. Page 2 of 3 3.3.2 Functional Layer A1 A2 A3 A4 Tin 4.0 - 6.0 1.0 - 4.0 0.15 - 1.5 2.5 - 4.5 Lead 14.0 - 20.0 18.0 - 27.5 20.0 - 27.5 12.0 - 16.0 Iron 0.7 m
7、ax 0.7 max 0.7 max 0.7 max Nickel - - - 0.7 max Total Others 0.75 max 0.75 max 0.75 max 0.75 max Copper Balance Balance Balance Balance Supplied composition shall fall within the above ranges, and limits will be defined as part of the control plan. 3.3.3 Overlay/Surface Coatings (as required by Engi
8、neering Drawing.) Thickness 18 - 30 micrometers (unless specified differently on Engineering Drawing). Lead 80 to 95% with either: a) Indium 5 10% b) in 7 - 16% c) Tin + Copper combined 8 - 20% and/or A Tin or Indium flash 3 micrometers max thickness. The steel back may be Copper or Tin flashed (3 m
9、icrometers maximum) to aid adhesion and corrosion protection if required. (Note: Plated Nickel flash allowed as diffusion barrier between overlay and functional layer). 3.4 ADHESION The bond between the bearing layer and the steel backing must withstand the following test : A sharp chisel with a cut
10、ting width of 10 mm minimum and a cutting angle of 40 - 50 will be forced at an angle of 30 - 60 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.
11、 3.5 HARDNESS (ISO 6507/ISO 6508/ASTM E 18, the average of 5 determinations minimum on the functional surface) A1 Cast A1 Sintered A2 & A3 Cast A2 & A3 Sintered A4 HV min 50 32 38 38 50 or HB min 45 30 35 35 45 ENGINEERING MATERIAL SPECIFICATIONWSD-M8A20-A1/A4Printed copies are uncontrolled Copyrigh
12、t 2003, Ford Global Technologies, Inc. Page 3 of 3 3.6 MICROSTRUCTURE The functional layer consists of a uniform distribution of Lead phases in a Copper rich solid solution matrix, and shall be bonded to the steel backing with no bonding or interface defects. Overlays, surface coatings, intermediate
13、 bonding and barrier layers, if present, 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.
