1、 ENGINEERING MATERIAL SPECIFICATION Date Action Revisions Rev 0 2013 08 22 Released G. Weber, NA Controlled document at www.MATS Copyright 2013, Ford Global Technologies, Inc. Page 1 of 5 ALUMINUM CASTING ALLOY, CYLINDER HEAD, LIGHT DUTY WSS-M2A178-A1 ALUMINUM CASTING ALLOY, CYLINDER HEAD, NORMAL DU
2、TY WSS-M2A178-A2 ALUMINUM CASTING ALLOY, CYLINDER HEAD, HEAVY DUTY WSS-M2A178-A3 1. SCOPE The materials defined by these specifications are heat treated aluminum-silicon casting alloys. 2. APPLICATION These specifications were originally released for materials used in manufacture of permanent mold c
3、ast cylinder heads. A1 Artificially over-aged aluminum-silicon-copper-magnesium alloy for light duty gasoline engine applications A2 Solution treated and artificially over-aged aluminum-silicon-copper-magnesium alloy for normal duty gasoline engine applications A3 Solution treated and artificially a
4、ged premium aluminum-silicon-copper-magnesium alloy for heavy duty gasoline and diesel engine applications 3. REQUIREMENTS 3.1 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to the Companys Standard Requirements for Production Materials (WSS-M99P111
5、1-A). 3.2 CHEMICAL COMPOSITION (Weight Percent) (ASTM E1479/ ASTM E1251) A1 A2 A3 Silicon, Si 6.0 8.5% 6.0 8.5% 6.5 7.5% Copper, Cu 2.8 4.0% 2.8 4.0% 0.40 0.60% Iron, Fe 0.80% max 0.80% max 0.20% max Magnesium, Mg 0.20 0.60% 0.20 0.60% 0.20 0.45% Nickel, Ni 0.30% max 0.30% max - Manganese, Mn 0.60%
6、max 0.60% max 0.15% max Zinc, Zn 0.80% max 0.80% max 0.10% max Titanium, Ti 0.25% max 0.25% max 0.25% max Lead, Pb 0.15% max 0.15% max - Tin, Sn 0.10% max 0.10% max - Strontium, Sr 60 150 ppm 60 150 ppm 60 400 ppm Calcium, Ca - - 20 ppm max Phosphorus, P - - 15 ppm max Others (Each) 0.05% max 0.05%
7、max 0.05% max Others (Total) 0.25% max 0.25% max 0.15% max Aluminum Balance Balance Balance Mn:Fe Ratio 1:2 min 1:2 min 1:2 min ENGINEERING MATERIAL SPECIFICATION WSS-M2A178-A1/A2/A3 Copyright 2013, Ford Global Technologies, Inc. Page 2 of 5 The composition shall be selected from within the above ra
8、nge. Specific composition limits and foundry practice to meet performance and manufacturing requirements will form part of the Control Plan for each individual component geometry and supplier. Ford and the supplier shall agree upon the test method(s) used for performing chemical analysis of molten a
9、luminum or cylinder head castings. The recommended method is optical emission spectroscopy (OES) (ASTM E1251), but inductively-coupled argon plasma spectroscopy (ICP) (ASTM E1479) may be used for research and failure analysis. In case of dispute over OES results, ICP shall be used as an umpire metho
10、d. 3.3 HEAT TREATMENT (Ford W-HTX, ASTM B917) Components shall be subjected to heat treatment as defined below, to achieve the required mechanical properties and dimensional stability. A1 T5-type treatment consisting of controlled cooling from casting temperature followed by artificial over-aging to
11、 stabilize the casting A2 T7-type treatment consisting of cooling from casting temperature, solution treatment, controlled quenching from solution treatment temperature and artificial over-aging the casting to a substantially stable condition A3 T6-type treatment consisting of cooling from casting t
12、emperature, solution treatment, controlled quenching from solution treatment temperature, and artificial aging to achieve maximum fracture resistance 3.3.1 Engineering Drawing Requirements Heat treatment parameters, including the appropriate quench medium, must be designed to achieve the required me
13、chanical properties and dimensional stability, and determined individually for each component. As appropriate for the required heat treatment process, the following process parameters shall be fully specified on the Engineering Drawing and reflected in the Supplier Control Plan, which is agreed upon
14、 between Ford and the supplier: Solution treatment temperature range and time at temperature range Maximum delay between solution treatment and quenching Quench medium Controlled air cooling parameters Minimum quench temperature and hold time Artificial aging temperature range and time at temperatur
15、e range 3.3.2 Restrictions A2 When a liquid quenching medium is used, the temperature of the quenchant at the beginning of quenching shall be not less than 90 C. A3 When a liquid quenching medium is used, the temperature of the quenchant at the beginning of quenching shall be not less than 60 C. 3.3
16、.3 Air Quenching Air quenching may be an acceptable alternative to liquid quenching for some applications, in which case details of the air quench process shall be included in the heat treatment process parameters. ENGINEERING MATERIAL SPECIFICATION WSS-M2A178-A1/A2/A3 Copyright 2013, Ford Global Te
17、chnologies, Inc. Page 3 of 5 3.4 CASTING QUALITY The cylinder head casting shall be free from laps, cold shuts, dross, and sludge, and shall have minimal eutectic segregation/depletion. Radiographic and metallographic assessment for gas porosity and shrinkage shall meet the general requirements defi
18、ned below, and may be further restricted in the Engineering Specification. Evaluation locations shall be defined in the Engineering Specification. 3.4.1 Radiographic Assessment (ASTM E155) Radiographic assessment for gas holes, gas porosity and shrinkage porosity shall be performed according to meth
19、ods described in ASTM E155. An assessment of Severity Level 3 or better is required for all defect types. 3.4.2 Metallographic Assessment The volume percent porosity shall be determined by image analysis over an area of 25 square millimeters, on contiguous fields of view, at a recommended magnificat
20、ion of 100X, and shall meet the requirements stated below in critical areas. Critical areas on the casting shall be defined in the Engineering Specification. Maximum size, minimum spacing and maximum grouping shall be specified in the Engineering Specification. A1 & A2 The average volume percent por
21、osity shall be 1% maximum, and no single area shall exceed 1.5%. A3 The average volume percent porosity shall be 0.2% maximum, and no single area shall exceed 0.5%. 3.5 MICROSTRUCTURE (ASTM E3) The microstructure shall consist of primary alpha aluminum, alpha aluminum-silicon eutectic, and intermeta
22、llic constituents. Efforts should be made to minimize copper segregation and needle-like intermetallics. Any needle-like intermetallics present in the microstructure shall not exceed 0.75 mm in length. The silicon component of the eutectic shall be modified to meet a minimum level of modification. A
23、FS eutectic modification of Level 4 or better is required in critical areas, and Level 3 or better in non-critical areas. Evaluation locations shall be defined in the Engineering Specification. 3.5.1 Secondary Dendrite Arm Spacing The Secondary Dendrite Arm Spacing (SDAS) shall be computed as the av
24、erage of 10 primary dendrites at 100X magnification, and shall meet the requirements stated below. Critical areas on the casting shall be defined in the Engineering Specification. All other areas are deemed non-critical. A1 A2 A3 Critical Areas Average SDAS, micrometers, max 30 30 25 Individual SDAS
25、, micrometers, max 45 45 35 Non-Critical Areas Average SDAS, micrometers, max 60 60 50 Individual SDAS, micrometers, max 75 75 65 ENGINEERING MATERIAL SPECIFICATION WSS-M2A178-A1/A2/A3 Copyright 2013, Ford Global Technologies, Inc. Page 4 of 5 3.6 MECHANICAL PROPERTIES (As Heat-Treated Components) T
26、est samples shall be machined from the component casting, after the appropriate heat treatment as described in section 3.3. Locations, frequency, and procedures of testing shall be outlined in the Engineering Specification and reflected in the Supplier Control Plan, which is agreed upon between Ford
27、 and the supplier. Elongation shall be determined by extensometer measurement. A1 A2 A3 3.6.1 Tensile Properties (ASTM B557) Deck Face Tensile Strength, MPa, min 230 230 280 0.2% Offset Yield Strength, min 175 200 220 Elongation, % min 1.0 1.0 4.0 Bolt Boss Tensile Strength, MPa, min 200 230 250 0.2
28、% Offset Yield Strength, min 170 180 190 Elongation, % min 0.5 0.5 3.0 3.6.2 Compressive Yield Strength, 180 180 190 0.2% Offset, MPa, min (ASTM E9) 3.6.3 Shear Strength, MPa, min 160 170 180 (ASTM B769) 3.6.4 Hardness, HBW (F/D2 = 10 recommended) (ASTM E10 / ISO 6506) Deck Face 85 - 120 85 120 85 1
29、20 All Other Locations 80 min 80 min 75 min Reporting of Brinell hardness measurements shall include the ball diameter (in mm) and the load (in kgf) used to measure the hardness, as required by the referenced test standards. For example, hardness measured using a 10 mm ball and 500 kgf load would be
30、 reported as HBW 10/500. 3.7 CONTROL OF MANUFACTURING PROCESS Ford Global Manufacturing Standard W-CMS defines a minimum set of required process controls for various casting processes. The casting process shall meet the requirements of W-CMS for Aluminum Permanent Mold processes. Ford Global Manufac
31、turing Standard W-HTX defines a minimum set of required process controls for various heat treatment processes. The specified heat treatment process shall meet the requirements of W-HTX for Aluminum Alloy Solution Heat Treating/Age Hardening. 4. GENERAL INFORMATION The information given below is prov
32、ided for clarification and assistance in meeting the requirements of these specifications. Contact for questions concerning Engineering Material Specifications. ENGINEERING MATERIAL SPECIFICATION WSS-M2A178-A1/A2/A3 Copyright 2013, Ford Global Technologies, Inc. Page 5 of 5 4.1 TYPICAL HEAT TREATME
33、NTS Descriptions of typical heat treatments to meet the requirements of these specifications are given below. These descriptions are not intended to be requirements, but rather guides to illustrate the information that is required to appear on the Engineering Drawing. Heat treatment parameters, incl
34、uding the appropriate quench medium, must be designed to achieve the required mechanical properties and dimensional stability, and determined individually for each component. A1 Controlled air cooling to achieve 90C max in less than 30 minutes Temperature at the start of controlled cooling: 475 +/-2
35、5 C Artificial aging: 220 +/-5 C for 3-4 hours A2 Solution treatment: 490 +/-5 C for 4-5 hours Quench Delay: 30 seconds maximum from furnace opening Quench: Water quench at 90 C minimum for 5 minutes minimum Artificial aging: 247 +/-5 C for 3-3.5 hours A3 Solution treatment: 525 +/-5 C for 4-5 hours
36、 Quench: Fan-assisted air cooling to 200 C in less than 5 minutes Artificial aging: 150 +/-5 C for 4-5 hours 4.2 CRITICAL AREAS Critical areas of the casting are generally defined as those locations were maximum material properties are required, such as the head deck face and bolt bosses. The component engineer, in cooperation with the materials engineer, is responsible for determining and designating critical areas on a casting. All areas deemed critical shall be defined in the Engineering Specification.
