1、 About the Aluminum Association The Aluminum Association, based in Washington, DC, with offices in Detroit, MI, represents U.S. and foreign-based primary producers of aluminum, aluminum recyclers and producers of fabricated products as well as suppliers to the industry. Member companies operate more
2、 than 200 plants in North America and many conduct business worldwide. Notice/Disclaimer The use of any information contained herein by any member or non-member of The Aluminum Association is entirely voluntary. The Aluminum Association has used its best efforts in compiling the information containe
3、d in this book. While the Association believes that its compilation procedures are reliable, it does not warrant, either expressly or implied, the accuracy or completeness of this information. The Aluminum Association assumes no responsibility or liability for the use of the information herein. All
4、Aluminum Association published standards, data, specifications and other technical materials are reviewed and revised, reaffirmed or withdrawn. Users are advised to contact The Aluminum Association to ascertain whether the information in this publication has been superseded in the interim between pu
5、blication and proposed use. ALUMINUM SOLDERING HANDBOOK Fifth Edition November 2004 CopyrightO 2004 The Aluminum Association, Inc. 900 19th St., N.W. Washington, DC 20006 www.aluminum.org The Aluminum Association. Inc. Technical Committee on Welding and Joining Mr. Tony Anderson Aico lec Wire Corpor
6、ation Mr. Bill Christy Alcan International Limited Mr. Kyle Williams Alcoa, Inc. Alcoa, Inc. Mr. Peter Pollak The Aluminum Association, Inc. Mr. Frank G. Armao Lincoln Electric Companynhe Mr. Donald J. Spinella Alcoa, Inc. Alcoa, Inc. The principles underlying soldering of aluminum are identical to
7、those that make met- allurgical bonding of other metals possible. After aluminums tough protective oxide coat- ing is removed, the soldering of aluminum proceeds along lines similar to those used with other metals, utilizing essentially the same techniques and equipment. Properly made, aluminum join
8、ts are long lasting, gas tight and strong. Depending on the solder chosen, aluminum joints can be as strong as the metal joined, When tested, these joints fail at the base metal. Aluminum is joined by soldering when many joints are to be made simultaneously and economically; when nearby material pre
9、cludes the higher heats of brazing and welding: when component distortion must be avoided; when temper loss is to be held to a minimum; when equipment investment funds are limited; and when rapid field repairs with hand-held tools are needed. Soldered aluminum joints are widely used in spacecrafi, e
10、lectronics, electrical power plants and power lines, household goods, refrigeration systems and air conditioning. The list of current and fiture solder applications is virtually endless. Library of Congress Catalog Card Number 74-1 73196 Use of the Information Any data and suggestions contained in t
11、his publication were compiled and/or developed by The Aluminum Association, Inc. In view of the variety of conditions and methods of use to which such data and suggestions may be applied, The Aluminum Association and its member companies assume no responsibility or liability for the use of informati
12、on con- tained herein. Neither The Aluminum Association nor any of its member companies gives any warranties, express or implied, with respect to this information. table of contents Chapter 1 Chapter 2 Chapter 3 Chapter 4 Chapter 5 Introduction to Aluminum Soldering Advantages of soldering Basic pro
13、cess Soldering with flux Soldering without flux Soldering without solder Solder heat Material for Soldering Breadth of choice of material Alloy temper and solderability Retention of temper Distortion eliminated Solderability and alloying elements Alloys and surface preparation Alloying elements and
14、intergranular penetration Wrought aluminum alloys most frequently soldered Solderable casting alloys Flux Organic fluxes Reaction fluxes Flux and intergranular penetration Fluxes for mixed-metal soldering Solder Soldering temperatures Abrasion solder Available solder forms Solder clad sheets Color m
15、atch Wiping solders Pre-Cleaning, Oxide Removal and Surface Preparation Measuring oxide thickness Oxide removal Keeping the parts clean Cleaning, oxide removal and joint qualitly Surface preparation-precoating Tinning Plating with chemical energy Alsan 70process Electroplating Local plating Postclea
16、ning and Finishing Organic flux residue Chloride flux residue removal Chloride-containing flux residue removal formulas Testing for flux traces Finishing Fixture and Joint Design Casual soldering Basic solder-joint parameters Solder joint requirements Joint clearance Suggested joint clearances 5 5 5
17、 6 6 7 7 8 8 8 8 8 8 10 10 12 12 12 12 14 15 15 16 18 18 18 18 19 19 20 20 21 22 23 23 24 24 25 25 25 26 26 26 27 27 28 29 29 29 29 30 30 1 table of contents Chapter 6 Chapter 7 Chapter 8 Chapter 9 Chapter 10 Chapter 11 Chapter 12 Joint types Calculating overlap Locked joints Designing corrosion res
18、istance into a joint Corrosion consideration when soldering to other metals Vibratory-load joint design Pressure-tight vessels Solder shape and quantity Solder placement Pre-positioning solder Dimensional changes at soldering temperatures Design for self-fixturing Fixture design Establishing and hol
19、ding joint clearance Applying flux Torch, Iron and Hot-Plate Soldering Torch and flux Massive parts and castings Automatic torch soldering Flux and iron Hot-plate soldering Abrasion and Ultrasonic Soldering Abrasion soldering Abrasion tool Solder Technique Ultrasonic soldering Ultrasonic solders Fur
20、nace Soldering Procedu re Time and temperature Heat distribution within the furnace Other Soldering Techniques-Reaction, Wipe, Induction, Dip and Radiant Heat Reaction flux soldering Wipe soldering Induction soldering Dip soldering Radiant heat soldering Soldering Castings Soldering Aluminum to Othe
21、r Metals and to Nonmetallics Choice of flux and solder Technique for mixed metal soldering Soldering aluminum to nonmetallics Joint Inspection, Testing and Performance Visual inspection 31 31 33 34 35 35 35 35 36 36 36 37 37 39 40 41 41 43 43 44 45 46 46 46 47 47 48 48 49 49 49 50 51 51 51 51 54 54
22、56 58 58 58 60 61 61 2 table of contents Nondestructive tests 62 Testing for leaks 63 Proof testing 63 Destructive inspection 63 Joint performance 64 Service temperatures 64 Corrosion resistance 64 Designing corrosion resistance into a joint 65 Flux and corrosion resistance 65 Protected joints 66 Co
23、rrosion resistance of dissimilar metal joints 66 Chapter 13 Safety measures 69 2-1 2-2 2-3 2-4 2-5 2-6 3-1 3-2 3-3 5-1 6- 1 11-1 12-1 12-2 12-3 Composition and solderability of wrought aluminum alloys Solderability of aluminum casting alloys Typical soldering fluxes Special-purpose corrosive fluxes
24、Composition of typical solders Solder and flux manufacturers Solderable oxide thicknesses Electroless baths for plating aluminum Chemical reduction plating baths Coefficients of thermal expansion Orifice diameter and gas pressure for soldering Solderability of aluminum to other metals and nonmetals
25、Solution potential of soldered metals Cathodic and anodic relationships Solder systems versus exposure to salt spray 9 10 13 16 17 18 21 25 25 37 41 59 65 65 68 fiqures 1-1 2-1 2-2 3- 1 3-2 3-3 3-4 3-5 4- 1 5- 1 5-2 5-3 5-4 5-5 5-6 5-7 Return bends on automatically soldered all-aluminum heat exchang
26、er Solder forms Effect of composition of zinc solders, soldering time and soldering temperature on rate of inter- alloying between zinc solders and aluminum alloy 6061 Self-contained ultrasonic cleaning system Surface resistance versus time for two caustic solutions Typical buildup of oxide on pure
27、aluminum alloys X-ray of carefully cleaned and deoxidized solder joints X-ray of solder joints comprising a similar unit; the joints were neither degreased nor deoxidized Personnel protection Joint clearance effects Variable dimension design Excellent socket joint design Vent holes Venting shape var
28、iations Solder joint designs frequently used with aluminum Weep holes 7 11 15 21 22 23 24 24 27 30 31 31 32 32 32 33 3 fisures 5-8 5-9 5-1 O 5-1 1 5-1 2 5-1 3 5-1 4A 5-1 46 5-1 5 5-1 6 6-1 6-2 6-3 6-4 6-5 7-1 7-2 7-3 8-1 8-2 9-1 9-2 9-3 9-4 9-5 9-6 10-1 10-2 11-1 11-2 12-1 12-2 12-3 12-4 12-5 12-6 C
29、alculating needed overlap by formula Lock seam designs Design for condensation Typical soldered joints that have proven suitable for pressure-tight containers Soldered joints after internally and externally positioned ring of solder has been used Twenty-one suggestions for making assemblies to be so
30、ldered self-fixtu ring How C-clamp springs may be used to hold parts lightly but dependably during soldering Simple, spring-loaded fixture serves an assembling and aligning aid How prick punch indentations and similar protrusions may be used to center and hold part in place Example of how an offset
31、may be used to establish and hold joint clearance between parts while they are being soldered Torch soldering is simple and rapid Typical setup for soldering a tee joint Automatic torch soldering an experimental air conditioning condenser Simple setup for soldering a lap joint with an iron or torch
32、Hot-plate soldering Simple, table-top supports for holding work pieces immobile when abrasion soldering Simple guide and weight arrangement to hold parts in alignment when tinned surfaces are heated for joining Typical ultrasonic soldering pot Furnace soldering fixturing Two temporary shields, faste
33、ned to walls of furnace, retard heating o solder and flux Self-spacing lap joints soldered with reaction flux alone Wipe soldering a splice between two cable sheaths Induction soldering Induction coil forms Small dip soldering pot in production use Electrically powered radiant heat soidering equipme
34、nt Repair of casting surface holes Examples of castings that have been soldered Magnified cross-sectional view of aluminum soldered to steel with zinc solder Intermetallic interface layer between alloy 3003 aluminum and the 70-30 brass plate Example of good socketed tube joint Example of good galvan
35、ized steel to aluminum plate soldered joint Oscillograph displays solder joint homogeneity Approximate electrical potential developed across low-temperature solder joint and zinc solder joint Copper-plated joint walls have more positive potential than the aluminum Effect of chloride-containing flux
36、residue on electrical resistance of aluminum-to-copper joint exposed to industrial atmosphere 33 34 35 35 37 38 39 39 39 39 42 42 44 45 45 47 47 48 50 50 52 52 53 53 54 55 57 57 59 59 62 62 63 66 66 67 4 Chapter One Introduction to Aluminum Soldering Soldering is an inexpensive and rapid means of pe
37、rma- nently joining aluminum to aluminum and to other metals. Properly made joints are leakproof and strong. Soldering is used for joining aluminum wires, making heat exchangers, spacecraft plumbing and thousands of other applications far too numerous to list here. Aluminum soldering is relatively s
38、imple. Single joints are readily made in the field and shop with low-cost hand tools. Single and multiple joints, often numbering in the thousands, are automatically produced with comparatively low-cost equipment by semiskilled personnel. Advantages of Soldering temperatures than either brazing or w
39、elding, assembly distor- tion due to soldering is generally nil. By the same token, sol- dered assemblies have lower temperature-induced stresses as compared to brazed or welded aluminum assemblies. The temperatures employed in soldering, the nature of the process and aluminums excellent thermal con
40、ductivity com- bine to make it reasonably easy to solder complex assemblies with varied sections. The fluxes normally used to solder aluminum are easier to remove than the fluxes normally used for brazing aluminum. There is also a group of aluminum soldering fluxes that, in many applications, do not
41、 need to be removed. (Certain organic fluxes are nonhygroscopic and noncorrosive.) By accepted American Welding Society definition, solder- ing is a joining process wherein coalescence between metal parts is produced by heating to suitable temperatures gener- ally below 840“F, and by using a filler
42、metal having a liq- uidus not exceeding 840F (449C) and below the solidus of the base metals. The solder is usually distributed between the properly fitted surfaces of the joint by capillary attraction. Brazing, by the same definition, is a similar process accom- plished at temperatures above 840F b
43、ut below the melting point of the metals to be joined. Welding requires that the par- ent metals be brought to or above their melting points. As soldering is accomplished at lower temperatures than brazing (and at considerably lower temperatures than weld- ing), it is often possible, by proper selec
44、tion of alloy and a low temperature solder, to solder aluminum with little loss of parent metal temper. Brazing requires a following quenching and aging treatment to restore temper. (This is only possible with heat-treatable alloys.) Remelting temperatures of sol- dered joints are too low to permit
45、solution heat treatment of soldered assemblies in heat-treatable aluminum alloys. In contrast to welding, the heat of soldering (and brazing) is fairly evenly distributed. Part expansion and subsequent contraction associated with soldering is far less an obstacle to precise joining than the inter-pa
46、rt motion generated by the intense, concentrated heat necessary for welding. As soldering does not need to be followed by quenching (to restore temper) and as soldering is accomplished at lower Aluminum may be soldered with a wide range of solders, a wide range of temperatures and a variety of fluxe
47、s. Brazing aluminum is accomplished in a narrow range of temperatures just below the melting point of the parent metal. Only a lim- ited variety of fluxes are currently available for brazing. Soldering therefore offers the designer greater flexibility within its scope. Aluminum is brazed at temperat
48、ures no more than about 50F below the solidus temperature of the base metal, and frequently closer. Aluminum soldering temperatures are, at a minimum, 200F below the solidus temperature of the base metal. Temperature control with aluminum soldering is there- fore considerably less stringent and dema
49、nding than that nec- essary for brazing. Less skill is required on the part of the torch operator to keep from melting the base metal when sol- dering than when brazing. (The solidus temperature of a metal marks the onset of melting. Liquidus marks the thermal point at which the metal is completely liquid. Between its solidus and liquidus temperature points, a metal is semi- liquid or slushy.) Soldering aluminum is relatively simple. Written instruc- tions are all that is needed for casual forming of joints. Commercial-quality soldering can be q
