1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW15665 Aluminum Extrusions for Structural Applications Copyright 2013 General Motors Company All Rights Reserved July 2013 Page 1 of 14 1 Scope 1.1 Material Description. This specification covers the chemical composition, mechanical propertie
2、s, surface quality, and structural integrity requirements of aluminum alloy hollow and semi-hollow extruded profiles produced from welding chamber (i.e., spider, porthole, or bridge) dies, solid profiles, solid round bars, and flat sheets. Refer to the Aluminum Association Aluminum Standards and Dat
3、a Manual - Metric International System of Units (SI) and/or EN 755-1 for definitions of hollow, semi-hollow and solid aluminum extrusions. 1.1.1 Aluminum extrusions may be supplied in straight as-extruded lengths, or bent to meet desired part shape. Secondary forming operations (i.e., formation of c
4、rush initiators, flats, flanges) shall be performed before artificial aging heat treatment. For round aluminum alloy extruded tubing intended for hydroformed components, refer to GMW16866 “Hydroformed Extruded Aluminum Mechanical Tubing and Components”. 1.1.2 The aluminum extrusion alloy and temper
5、designations contained in this specification shall include aluminum alloys with temper mechanical property limits documented in a regional national standard - Aluminum Association (AA), European Standard (EN), ASTM International (ASTM), Japanese Industrial Standards (JIS). In this specification, alu
6、minum extrusion alloy and temper designations that conform to regional national standards shall be designated as standard grades. 1.1.2.1 Aluminum extrusions with modified alloys and/or tempers that deviate from regional national standards shall be designated as non-standard grades. Aluminum extrusi
7、on alloys with chemical composition limits that do not conform to regional national standard chemical composition limits shall be designated as proprietary chemical composition grades. Non-standard and proprietary composition grades are divided into two categories: minimum yield strength based grade
8、s and nominal yield strength based grades. Nominal yield strength based grades are applicable to bumper system components known as crush cans, crash boxes or danner boxes. 1.1.3 Material Identification. This specification shall be referenced in engineering math data files or engineering drawing mate
9、rial specifications. The material specification shall consist of the General Motors Worldwide (GMW) specification number, the materials type, non-ferrous metal type, alloy designation, the temper designation and minimum or nominal yield strength. See Section 8 “Coding System” for further explanation
10、. 1.2 Symbols. A50, 5D, 5.65(So)0.5, A, A5, . 1.3 Typical Applications. Typical applications include body, closure, exterior and chassis structural applications. Refer to GM Materials Engineering or the Global Preferred Materials Catalog for selection of appropriate extrusion materials for specific
11、applications. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. ASTM B557M ASTM E101 EN 755-1 EN 10002-1 ASTM E34 ASTM E1251 EN 755-9 ISO 8493 2.2 GM Standards/Specifications. GMW3011 GMW16170 GMW16721 GMW3059 GMW1
12、6549 GMW16866 2.3 Additional References. Aluminum Association Aluminum Standards and Data Manual Metric International System of Units (SI). Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license
13、from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15665 Copyright 2013 General Motors Company All Rights Reserved July 2013 Page 2 of 14 Aluminum Association Publication QCA-2, “Visual Quality Characteristics of Aluminum Extrusions”. General Motors Material Property Database (GMMPD). Global Preferr
14、ed Materials Catalog. GP-12/Safe Launch TMC003 Material Safety Data Sheet guidance documents (available at ). 3 Requirements 3.1 Chemical Composition. Base metal composition shall conform to the requirements in Table A1. The base metal chemical composition shall be determined per ASTM E34, ASTM E101
15、 or ASTM E1251. In cases of dispute, referee method shall be ASTM E34. Suppliers of proprietary chemical composition grades shall report chemical composition limits for Prototype, Production Part Approval Process (PPAP), GP-12/Safe Launch and Production data submissions. 3.2 Mechanical Properties. 3
16、.2.1 As-Received Mechanical Properties. Specimen sampling shall be conducted per Aluminum Association Aluminum Standards and Data Manual Metric SI, or EN 755-1. The 0.2% offset yield strength, ultimate tensile strength, and percent total elongation in 50 mm or 5D/5.65(So)0.5 gauge length shall be de
17、termined per ASTM B557M or EN 10002-1, respectively. 3.2.1.1 Standard Grade. Standard grades are identified by alloy designation (i.e., 6063, 6061, etc.,) or alloy designation followed by a capital letter suffix (i.e., 6005A, 6005C, etc.,) temper designation (i.e., T4, T5, T6), followed by minimum y
18、ield strength value. Standard grades furnished to this specification shall conform to the mechanical property values shown in Table A2. 3.2.1.2 Non-standard and Proprietary Chemical Composition Grades. Non-standard grades are identified with a capital letter suffix after the alloy designation (i.e.,
19、 7003A, 7003B, etc.,) and/or temper designation (i.e., T5A, T6A, T7A) followed by minimum, or nominal yield strength value. Proprietary chemical composition grades are identified by the specific numerals “6000” or “7000” with a capital letter suffix after these numerals (i.e., 6000A, 7000A), and tem
20、per designations (i.e., T5A, T6A, T7A), followed by minimum or nominal yield strength value. Non-standard and proprietary chemical composition minimum yield strength grades are shown in Table A3. Non-standard nominal yield strength grades are shown in Table A4. 3.2.2 Post-Paint Bake Mechanical Prope
21、rties. Aluminum Extrusions may show significant tensile mechanical properties changes following E-coat and paint (i.e., primer surfacer, basecoat, topcoat) bake processing. Supplier may be required to modify extruded aluminum profile artificial aging practice in order to assure that aluminum extrusi
22、ons exceed minimum tensile mechanical property requirements after GM assembly plant E-coat and paint bake processing. 3.2.3 Allowed Alloy Substitutions. If necessitated by global availability or commercial restrictions, it is permissible to substitute 6060 alloy with 6063 alloy or substitute 6063 al
23、loy with 6060. If an alloy substitution is made, the final extruded component must meet the mechanical property requirements of the originally specified material grade. When material and part qualifications are granted based on extrusions produced from a particular alloy (6060 or 6063), re-qualifica
24、tion will be required prior to substitution of the alternate alloy (6063 or 6060). 3.2.4 Mechanical Properties After Simulated Elevated Temperature Exposure. Suppliers of aluminum extrusions to be used in elevated temperature vehicle locations such as the motor compartment, and near the exhaust syst
25、em shall submit mechanical property data on extrusions following elevated temperature exposure. Supplier shall submit yield strength, ultimate tensile strength and total elongation measurements on aluminum extrusions samples following 205 C (401 F) exposure for one (1) hour, and 150 C (302 F) exposu
26、re for one thousand (1000) hours. 3.3 Surface Requirements. 3.3.1 Surface Quality. Aluminum extrusions supplied to this specification shall be free of surface imperfections that may compromise the structural integrity of extrusions. Surface imperfections include, but are not limited to blisters, cor
27、rosion pits, blowholes, orange peel, stretcher jaw marks, and speed tears. Refer to Aluminum Association publication QCA-2, “Visual Quality Characteristics of Aluminum Extrusions” for photographs and definitions of imperfections. Surface imperfections that are judged to be cosmetic and do not compro
28、mise the structural integrity may be acceptable provided that boundary samples are provided to GM Materials Engineering to document location and severity. Suppliers may be required to prove cosmetic imperfections do Copyright General Motors Company Provided by IHS under license with General Motors C
29、ompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15665 Copyright 2013 General Motors Company All Rights Reserved July 2013 Page 3 of 14 not compromise structural integrity. Boundary samples shall be established on a part n
30、umber by part number basis. 3.3.2 Surface Preparation. Aluminum extrusions shall be free of white corrosion (aluminum oxide) and pitting. Processing compounds (lubricants, cutting fluids, marking inks, etc.,) and corrosion preventative compounds applied to aluminum extrusions that will be processed
31、through GM assembly plants shall be capable of being removed during paint system cleaning operation. 3.4 Product Integrity. 3.4.1 Internal Integrity. Aluminum extrusion supplied to this specification shall be free of internal imperfections that may compromise the structural integrity. Internal imper
32、fections include, but are not limited to laminations, unhealed billet cracks, porosity, and stringer inclusions. Refer to Aluminum Association publication QCA-2, “Visual Quality Characteristics of Aluminum Extrusions” for photographs and definitions of imperfections. Supplier process control plan sh
33、all show manufacturing procedures used to assure aluminum extrusion internal integrity. 3.4.2 Back End Condition. Aluminum extrusions supplied to this specification shall be free of oxides and inclusions commonly known as “Back End Condition”. Suppliers shall process billets such that butt ends are
34、sheared in such a way to avoid the presence of this condition in extruded profiles. 3.4.3 Transverse Weld Seams. Aluminum extrusions supplied to this specification shall not contain transverse weld seams. Suppliers shall process extrusions such that transverse weld seams are removed from extruded pr
35、ofiles. 3.4.4 Longitudinal Weld Seams. Longitudinal weld seam integrity shall be demonstrated by subjecting hollow aluminum extrusions to a drift expansion test per ISO 8493. Profiles shall be subjected to increasing load until fracture occurs. Satisfactory fracture surfaces shall exhibit 100% ducti
36、le fracture (i.e., dimple rupture, micro void coalescence) characteristics. Fracture surfaces exhibiting any smooth, featureless surfaces characteristics shall be judged to be unsatisfactory. If necessary, examine fracture surfaces with scanning electron microscope for confirmation. See Figure B1 fo
37、r schematic diagram showing longitudinal weld seam evaluation by drift test method. For specific details refer to ISO 8493 - Metallic MaterialsTubeDrift Expanding Test. 3.4.5 Stress-Corrosion Resistance. Stress Corrosion Cracking (SCC) can be caused by the combination of sustained tensile stress and
38、 a corrosive service environment resulting in premature failure of parts along grain boundaries. Varying amounts of copper in the alloy influence SCC differently. Hence, alloy percentages in materials, fabricating methodologies, heat treatment methods, loading paths, etc., shall be carefully selecte
39、d to minimize SCC so as to meet the durability requirements of components. 3.5 Processing Requirements. 3.5.1 Zinc Phosphate and/or Nano Ceramic Conversion Coating Analysis. For aluminum extrusions that will be painted, aluminum extrusion supplier shall have zinc phosphate and/or nano ceramic conver
40、sion coating analysis performed on production representative aluminum extrusion samples. Zinc phosphate shall meet GMW3011 crystal size, coating thickness and coating weight requirements. Nano ceramic conversion coatings shall meet GMW16170 coating thickness and coating weight requirements. Aluminum
41、 extrusion suppler shall provide sample to GM materials engineer for analysis performed by GMW3011 zinc phosphate supplier and/or GMW16170 nano ceramic conversion coating supplier, or a GM approved independent testing laboratory. 3.5.2 Adhesive Compatibility. When applicable, aluminum extrusions sup
42、plied to this specification shall meet the adhesive compatibility requirements of GMW16549. Testing shall be performed on an aluminum extrusion sample which has been subjected to production representative processing compounds (lubricants, cutting fluids, marking inks, etc.,) and/or corrosion prevent
43、ative compounds. Aluminum extrusions may require pre-treatment (i.e., conversion coating) processing per GMW16721 prior to adhesive bonding. 3.5.3 Joining. When applicable, aluminum extrusions supplied to this specification shall be suitable for welding and mechanical clinching by standard methods.
44、3.6 Additional Requirements. 3.6.1 Dimensions and Dimension Tolerances. Unless specified on the engineering drawings or math data files, aluminum extrusions dimensions and dimension tolerances shall conform to the Aluminum Association Aluminum Standards and Data Manual Metric International System of
45、 Units (SI) and/or EN 755-9. Depending Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW15665 Copyright 2013 General Motors Company All Ri
46、ghts Reserved July 2013 Page 4 of 14 on supplier capability and component performance requirements, more restrictive dimension tolerances may be required. 3.6.2 GM Material Property Database Sample and Data Submission. Upon request, aluminum extrusion supplier shall submit samples to GM Material Eng
47、ineering representative to generate data for the GM Material Property Database. Samples shall be at least 200 mm (8 in) in length. Supplier shall also be prepared to provide physical properties (i.e., Elastic Modulus, Density), and thermal properties (i.e., Coefficient of Linear Thermal Expansion, T
48、hermal Conductivity, Specific Heat) upon request. 4 Manufacturing Process Not applicable. 5 Rules and Regulations 5.1 Legal Regulations. All materials must satisfy applicable laws, rules, regulations and recommendations valid in the country of usage. 5.2 Language. In the event of conflict between th
49、e English and domestic language, the English language shall take precedence. 5.3 Inspection and Rejection. Samples of components or materials released to a GM material specification shall be tested for conformity with the requirements of this material specification and approved by the responsible Engineering department prior to commencement of delivery of bulk supplies. A new approval must be received for any changes, e.g., properties, manufacturing proc
