1、 ENGINEERING MATERIAL SPECIFICATIONDate Action Revisions 2006 10 23 Activated A. Barros Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 1 of 3 ALUMINUM CASTING ALLOY, ENGINE CYLINDER HEAD, AS-CAST CONDITION WSS-M2A169-A 1. SCOPE The material defined by this specifi
2、cation is a special aluminum “as-cast“ alloy with titanium and high copper content. 2. APPLICATION The alloy was originally developed to be used for South American engine cylinder heads produced by die cast and precision sand casting process without heat treatment. For use in other regions, consult
3、your local Materials Engineering Activity. 2.1 LIMITATIONS 2.1.1 This specification is intended for use only in South America. 2.1.2 The materials described in this specification are intended to be used in the “as-cast“ (un-heat treated or F Temper) condition. 2.1.3 The materials described in the sp
4、ecification may not be stable when subjected to engine running temperatures. Dimensional growth/distortion accompanied by increase in yield strength and a decrease in % elongation could occur. 2.1.4 Slowly solidifying regions of this cylinder head may exhibit copper segregation associated with macro
5、/micro shrinkage due to the presence of strontium, which may adversely affect material properties 2.1.5 Design and Manufacturing Engineers should measure/evaluate microstructure in critical areas and understand the potential dimensional changes, which may occur at engine operating temperature prior
6、to releasing a new design. 3. REQUIREMENTS Material specification requirements are to be used for initial qualification of materials. 3.1 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers must conform to the Companys Standard Requirements for Production Materials (
7、WSS-M99P1111-A). ENGINEERING MATERIAL SPECIFICATIONWSS-M2A169-A Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 2 of 3 3.2 CHEMICAL COMPOSITION (Weight Percent) (ASTM E 1479/ASTM E 1251 Suggested): Si: 8.00 - 9.50 Cu: 4.30 - 5.00 Mn *: 0.30 - 0.50 Mg: 0.50 - 0.70 T
8、i: 0.10 - 0.20 Sr: 0.012 - 0.02 Fe: 0.75 max Ni: 0.30 max Zn: 0.70 max Ca: 0.003 max Each Other Elements 0.05 max Total Other Elements: 0.50 max Al: Remainder *: The Mn minimum composition have to equal or more than the proportion wt%Mn = 0.5 X wt%Fe, see General Information. 3.3 MECHANICAL PROPERTI
9、ES AND HARDNESS The following mechanical properties are minimum values. Properties measured on samples cut from castings. The position where samples must be cut from parts must be stated on Engineering Drawing, Engineering Specification, SDS or other Engineering document. Mechanical properties of ca
10、stings depend on process parameters - cooling rates, wall thickness, temperatures, etc. If part geometry requires deviations from the mechanical property requirements below, the deviations must be stated on the Engineering Drawing. Tensile properties according to ASTM B 557, compressive properties a
11、ccording to ASTM E 9, shear properties according to ASTM B 769, fatigue limit according ASTM E 466 and hardness according to ASTM E 10. During the production the control items are: tensile strength, yield strength, elongation and hardness. 3.3.1 Tensile strength (ASTM B 557), min 190 MPa 3.3.2 Yield
12、 strength, 0.2% Proof Stress (ASTM B 557), min 150 MPa 3.3.3 Shear Strength (ASTM B 769), min 130 MPa 3.3.4 Compressive Yield (ASTM E 9), min 130 MPa 3.3.5 Elongation (ASTM B 557), min 0.7% 3.3.6 Fatigue limit at 5x108 (ASTM E 466), min 55 MPa 3.3.7 Hardness (ASTM E 10), min 75 HB ENGINEERING MATERI
13、AL SPECIFICATIONWSS-M2A169-A Printed copies are uncontrolled Copyright 2006, Ford Global Technologies, LLC Page 3 of 3 3.4 MICROSTRUCTURE Microstructure of castings also depends on process conditions. For aluminum engine cylinder heads made with the alloy described in this specification, the microst
14、ructure shall be as follows. Eutectic modification shall be achieved with strontium, which shall be added to the alloy just before injection of parts (see “general information“). Manganese is added to form the Chinese script phase in the iron rich intermetallics phases and minimize the beta Fe phase
15、 formation in the ratio of 95% of Chinese script phase and 5% of beta Fe phase (see “general information“). Matrix -Al dendrites -Al-Si Eutectic Modified Primary Si intermetallics Undesirable 4. GENERAL INFORMATION This specification was developed for cylinder head castings made in the “as-cast“ con
16、dition. The alloy may be delivered in both liquid and solid (ingot) form. The strontium is added to the alloy just before casting to prevent fading. A late addition of titanium-bearing alloy is used to produce grain refinement. The best mechanical properties are obtained with the smallest grain size (typically 25 - 40 micron range). Manganese is added equal a minimum of: Mn = 0.5 X wt%Fe to enhance formation of the Fe-Mn-Si Chinese script phase and to minimize amount of the brittle beta Fe phase.
