1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.QUESTIONS REGARDING THIS DOCUMENT: (724) 772-8512 FAX: (724) 776-0243TO PLACE A DOCUMENT
3、 ORDER; (724) 776-4970 FAX: (724) 776-0790SAE WEB ADDRESS http:/www.sae.orgCopyright 1989 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001INFORMATIONREPORTAn American National StandardJ1434REAF.JAN89Issued 1983
4、-06Reaffirmed 1989-01WROUGHT ALUMINUM APPLICATIONS GUIDELINESForewordThis Reaffirmed Document has not changed other than to put it into the new SAE Technical StandardsBoard Format.1. ScopeThis report approaches the material selection process from the designers viewpoint. Information ispresented in a
5、 format designed to guide the user through a series of decision-making steps. “Applicationscriteria“ along with engineering and manufacturing data are emphasized to enable the merits of aluminum forspecific applications to be evaluated and the appropriate alloys and tempers to be chosen.2. Reference
6、s 2.1 Applicable Publications2.1.1 SAE PUBLICATIONAVAILABLE FROM SAE, 400 COMMONWEALTH DRIVE, WARRENDALE, PA 15096-0001.SAE J399Anodized Aluminum Automotive Parts3. General CharacteristicsIn summary, aluminum is a suitable material for automotive applications. Itsperformance is a function of the deg
7、ree to which its characteristics - which are different from steel - arerecognized and taken into account in the design, fabrication, and assembly operations.3.1 StrengthTypical property characteristics are illustrated in Figures 1 and 2. Commercially pure aluminumhas tensile yield and ultimate stren
8、gths of about 50 MPa (7 ksi) and 90 MPa (13 ksi). Values approaching 500MPa (73 ksi) and 600 MPa (87 ksi) can be obtained with a combination of the following:a. Working the metal, as by cold rolling and forming.b. Alloying aluminum with small percentages of one or more other metals such as manganese
9、, silicon,copper, magnesium, or zinc.c. Heat treatment and aging, as in the case of heat-treatable alloys. As a general rule, there is areduction in elongation as yield and ultimate strengths of an aluminum alloy are increased by coldwork or heat treatment. For alloys having a tensile yield strength
10、 of 500 MPa (73 ksi), elongations varyfrom 812%.The strength and modulus of aluminum and its alloys decrease at elevated temperatures, although somealloys retain good strength at temperatures up to 200260C (400500F). At sub-zero temperatures,however, their strength increases without loss of ductilit
11、y so that aluminum is a particularly useful metal for low-temperature applications.Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE J1434 Reaffirmed JAN89-2-3.2 FatigueComponents subjected to repeat
12、ed loads should be carefully checked for the possibility of fatiguefailure. Aluminum does not exhibit well-defined endurance limits. Typically, the endurance limits published foraluminum alloys are based on 500 million cycles. More data are being generated at 10 million cycles.Limited strain control
13、 life data are also available. An S/N curve representing the design condition is required totake full advantage of an aluminum alloy when designing for fatigue. Connections, joints, holes, or otherfeatures that cause stress concentrations are areas subject to fatigue, especially with aluminum alloys
14、. Carefuldesign can reduce concentrations in highly stressed areas, thereby making the most efficient use of thematerial. All changes between different cross sections within a component should be gradual, as smoothtransitions produce an improvement in the fatigue life of a component. In the assessme
15、nt of fatigue, it isinvaluable to compare available test data for joints similar to those of interest.3.3 Corrosion ResistanceAluminum alloys are known for their excellent atmospheric and road salt corrosionresistance, which results from the tightly adherent natural oxide film present on the surface
16、. In many instances,aluminum alloys can be exposed to industrial and seacoast environment with no protection; others may requirea protective coating at least on faying surfaces. In situations where crevices and pockets allow accumulation ofmud and road salts and at junctions with dissimilar metals (
17、galvanic couples), the corrosion protection of thenatural oxide is insufficient and severe corrosion damage can occur. The former conditions should be avoidedwhere possible in the design stage (for example, elimination of shelves, incorporation of drain holes, etc.). Theelimination of the latter gal
18、vanic joints is extremely difficult or impossible in most ground transportationapplications and various combinations of coatings and insulation techniques must be utilized.Certain alloys, especially those containing over 3% magnesium and magnesium/zinc can be susceptible tostress corrosion cracking.
19、 This susceptibility must be considered in design and testing and care should beexercised in selecting appropriate alloys and tempers when designing structural members from these alloys.3.4 FinishingAluminum needs no protective coatings for many applications. In many instances, the surfacefinish sup
20、plied is entirely adequate without further finishing. Where the plain aluminum surface does notsuffice, or where decoration or additional protection is required, a wide variety of surface finishes such aschemical, electrochemical, and paint finishes may be applied.Chemical conversion coatings are av
21、ailable for additional corrosion protection. They also provide an excellentbase for paint. Electroplating procedures have been developed to give aluminum an attractive, durable finish.Anodic coatings are used for both decorative and functional applications. Hardcoat anodized aluminumsurfaces can pro
22、vide wear resistance similar to case-hardened steel. Vitreous enamels have also beendeveloped for aluminum.3.5 FabricationAluminum can be cast, stamped, drawn, extruded, forged, spun, roll formed, and cold impacted.Typical aluminum body-sheet alloys are not as formable as low-carbon steel, but are c
23、omparable to high-strength low-alloy steels. Aluminum can be fabricated on conventional press lines with modifications in tooling,lubrication, and handling. Formability considerations should be taken into account in the initial design phase.3.6 MachinabilityThe high speed with which many aluminum al
24、loys may be machined is an important factor indetermining the manufacturing cost of aluminum parts. Aluminum may be turned, milled, bored, or machinedat the maximum speeds of which most machines are capable. An example of this is aluminum rod and baremployed in the high speed manufacture of parts by
25、 automatic screw machines.3.7 JoiningAluminum may be resistance welded, arc welded, brazed, soldered, and adhesive bonded. It mayalso be joined by mechanical systems such as hemming, riveting, clinching, pierce riveting, bolting, andstitching. Resistance welding, clinching, and riveting may be combi
26、ned with adhesives for improved strengthand fatigue life. Resistance spot welding, for high-speed production applications, is in the developmentalphase.3.8 Electrical ConductivityElectrical conductor grades of aluminum have 62% of the current carrying capacityCopyright SAE International Provided by
27、IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE J1434 Reaffirmed JAN89-3-of copper in equal volumes. These grades of aluminum have equal current carrying capacity at 1/2 the weightof copper. The high electrical conductivity property has
28、led to the widespread use of aluminum inelectromagnetic radiation shielding.3.9 Magnetic PropertiesAluminum is nonmagnetic if sufficiently free from paramagnetic impurities such as iron.This property has led to the use of aluminum in sensitive mechanical and electronic devices.3.10 Thermal Conductiv
29、ityThe high thermal conductivity of aluminum has led to its extensive use in radiators,heat exchangers, heat sinks, and other devices that involve the transfer of thermal energy.3.11 ReflectivityAluminum is an excellent reflector of radiant energy through the entire range of wavelengths,from ultravi
30、olet through the visible spectrum and infrared heat waves. It is used for heat shields. It also reflectselectromagnetic wavelengths in the radio and radar range. Aluminum has a light reflectivity of over 80% whichhas led to its wide use in automotive trim, reflectors, and in lighting fixtures.4. All
31、oy and Temper Designation Systems4.1 The Metallurgy of AluminumThis section is intended to give the automotive designer a brief overview ofthe different types of alloys available and an indication of the effects of alloying elements. The numerical alloydesignation system adopted by the aluminum indu
32、stry is based on the principal alloying elements in each classof alloy.In high-purity form, aluminum is soft and ductile. Most automotive uses, however, require greater strength thanpure aluminum offers. This is achieved in aluminum first by the addition of other elements which singly, or incombinat
33、ion, impart strength to the metal to produce various alloys. Further strengthening is possible by heattreatment and cold work.4.1.1 NON-HEAT-TREATABLE ALLOYSThe initial strength of alloys in this group depends on the hardening effectprovided by manganese, silicon, iron, and magnesium, singly, or in
34、various combinations. The non-heat-treatable alloys are usually designated as the 1000, 3000, 4000, or 5000 series. Further, strengthening isachieved by various degrees of cold working, denoted by the “H“ series of tempers. Alloys containingappreciable amounts of magnesium, when supplied in strain-h
35、ardened tempers, are usually given a finalelevated-temperature treatment called stabilizing to insure stability of properties.4.1.2 HEAT-TREATABLE ALLOYSThe initial strength of alloys in this group is enhanced by the addition of alloyingelements such as copper, magnesium, zinc, and silicon. These al
36、loys are designated as the 2000, 6000, or7000 series.It is possible to subject them to thermal treatments which will impart pronounced strengthening, denoted bythe “T“ series of tempers.The first step, called heat treatment or solution heat treatment, is an elevated-temperature process designedto pu
37、t the soluble element or elements in solid solution. This is followed by rapid quenching, usually in water.At room or elevated temperature, the alloys are not stable after quenching and precipitation of theconstituents from the super-saturated solution begins. After a period of several days at room
38、temperature,termed aging or room-temperature precipitation, the alloy is considerably stronger. Many alloys approach astable condition at room temperature, but some alloys, particularly those containing zinc magnesium or zincwith magnesium and copper, continue to age harden for long periods of time
39、at room temperature.By heating for a controlled time at slightly elevated temperatures, further strengthening is possible andproperties are stabilized. This process is called artificial aging or precipitation hardening. By the propercombination of solution heat treatment, quenching, cold working, an
40、d artificial aging, the highest strengthsare obtained.Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-SAE J1434 Reaffirmed JAN89-4-4.1.3 ANNEALING CHARACTERISTICSAll wrought aluminum alloys are availab
41、le in annealed form. In addition, itmay be desirable to anneal an alloy from any other initial temper, after working, or between successivestages of working such as in deep drawing.4.2 Alloy Designation System and Effect of Alloying Elements4.2.1 1000 SERIESAluminum of 99% or higher purity. This ser
42、ies has many applications especially in theelectrical and chemical fields and is characterized by excellent corrosion resistance, high thermal andelectrical conductivity, low mechanical properties, and excellent workability. Moderate increases in strengthmay be obtained by strain hardening. Iron and
43、 silicon are the major impurities.4.2.2 2000 SERIESCopper is the principal alloying element in this group. These alloys require solution heattreatment to obtain optimum properties. The heat-treated condition has mechanical properties that aresimilar to, and sometimes exceed, those of mild steel. In
44、some instances, artificial aging is employed tofurther increase the mechanical properties. This treatment increases yield strength, with attendant loss inelongation; its effect on ultimate tensile strength is not as great.4.2.3 3000 SERIESManganese up to 1.5% is the major alloying element in this gr
45、oup of work-hardenable alloys.One of these is the alloy 3003 which is widely used as a general-purpose alloy for low to moderate strengthapplications requiring good workability.4.2.4 4000 SERIESThe major alloying element of this group is silicon, which can be added in sufficient quantitiesto cause s
46、ubstantial lowering of the melting point without producing brittleness in the resulting alloys. Forthis reason, aluminum-silicon alloys are used in welding wire and as brazing alloys where a lower meltingpoint than that of the parent metal is required. Alloys in this series are non-heat-treatable. W
47、hen used inwelding heat-treatable alloys, they will pick up some of the alloying constituents of the latter and so respondto heat treatment to a limited extent.4.2.5 5000 SERIESMagnesium is one of the most effective and widely used alloying elements for aluminum.When it is used as the major alloying
48、 element or with manganese, the result is a moderate to high strengthnon-heat-treatable alloy. Alloys in this series possess good welding and low temperature characteristics andgood resistance to corrosion in marine atmosphere. Certain limitations should be placed on the amount ofcold work and servi
49、ce temperatures for the higher magnesium content alloys (alloys with over 3%magnesium) to avoid susceptibility to intergranular forms of corrosion.4.2.6 6000 SERIESAlloys in this group contain silicon and magnesium and are heat-treatable.The magnesium-silicon (magnesium-silicide) alloys possess good formability and corrosion resistance, withmedium strength. Alloys in this heat-treatable group may be formed in the solution heat-treated conditionand then artificially aged to attain optimum properties.4.2.7 7
