Copper Development Association Cost-Effective Manufacturing: Joining of Copper and Copper Alloys Lou Brown CDA Publication No 98, 1994 Cost-Effective Manufacturing: Joining of Copper and Copper Alloys CDA Publication No 98 September 1994 Members as at 1st January 1994 ASARCO Inc Boliden MKM Ltd Thomas Bolton Ltd Brandeis Ltd The British Non-Ferrous Metals Federation Chile Copper Ltd Falconbridge Ltd Gecamines Commerciale IMI plc Inco Europe Ltd Noranda Sales Corporation of Canada Ltd Palabora Mining Co Ltd RTZ Limited Southern Peru Copper Corporation Acknowledgements The author is grateful to members of the Welding Institute (TWI), Loctite (UK) Limited, the British Non- Ferrous Metals Federation and the Association of Bronze and Brass Founders for helpful comment during the compilation of this handbook. The preparation of this publication has been financed by International Copper Association. Copper Development Association Copper Development Association is a non-trading organisation sponsored by the copper producers and fabricators to encourage the use of copper and copper alloys and to promote their correct and efficient application. Its services, which include the provision of technical advice and information, are available to those interested in the utilisation of copper in all its aspects. The Association also provides a link between research and user industries and maintains close contact with other copper development associations throughout the world. Website: www.cda.org.uk Email: [email protected] Copyright: All information in this document is the copyright of Copper Development Association Disclaimer: Whilst this document has been prepared with care, Copper Development Association can give no warranty regarding the contents and shall not be liable for any direct, indirect or consequential loss arising out of its use Contents Summary ......................................................................................................................................................4 Section 1 - Introduction...............................................................................................................................5 Section 2 - Selection of a Joining Process ..................................................................................................6 Section 3 - Bolting and Riveting .................................................................................................................6 Section 4 – Adhesive Bonding.....................................................................................................................9 Section 5 - Soldering..................................................................................................................................10 Recommended Solder Fluxes for Engineering Materials.............................................................................11 Copper, solid or plates, tin-bronzes, gunmetals.......................................................................................11 Copper-nickel alloys ...............................................................................................................................11 Copper-aluminium alloys (aluminium bronzes) ......................................................................................11 Gilding metals (CuZn10 and CuZn20)....................................................................................................11 Commercial brasses (CuZn30 and CuZn40) ...........................................................................................11 Soft Solder Filler Metals..............................................................................................................................11 Resistance Soldering....................................................................................................................................11 Section 6 - Brazing and Silver Soldering .................................................................................................17 The Brazing Process....................................................................................................................................17 Basic Principles.......................................................................................................................................17 Brazing Filler Metals...................................................................................................................................17 Copper-Silver Alloys...............................................................................................................................21 Copper-phosphorus-silver alloys.............................................................................................................22 Joint Design.................................................................................................................................................22 Joint Clearance........................................................................................................................................22 Joint Overlap...........................................................................................................................................23 Brazing Alloy Pre-placement ..................................................................................................................23 Physical and Metallurgical Factors..............................................................................................................24 The Coppers............................................................................................................................................24 Alloys Heavily Cold-worked, or with High Softening Temperatures......................................................24 Precipitation-hardening Copper Alloys...................................................................................................25 Alloys Containing Aluminium.................................................................................................................26 Alloys Containing Lead...........................................................................................................................27 Alloys Containing Tellurium or Sulphur.................................................................................................27 Section 7 - The Bronze Welding Process .................................................................................................28 Basic Principles ...........................................................................................................................................28 Filler Metals.................................................................................................................................................28 Joint Design.................................................................................................................................................29 Section 8 - Welding....................................................................................................................................31 Gas-shielded Arc Welding...........................................................................................................................31 Basic Principles and Processes................................................................................................................31 Pulsed Current TIG Process ................................................................................................................................ 31 Plasma Arc Process ............................................................................................................................................. 31 Fine-wire MIG Process ....................................................................................................................................... 32 Pulsed-current MIG Process................................................................................................................................ 32 Filler Metals ............................................................................................................................................33 Shielding Gases.......................................................................................................................................34 TIG Welding: ...................................................................................................................................................... 34 MIG Welding ...................................................................................................................................................... 34 1 Joint Design and Preparation .................................................................................................................. 34 Edge Preparation ................................................................................................................................................. 34 Pre-weld and Inter-run Cleaning ......................................................................................................................... 36 Jigging and Backing Techniques......................................................................................................................... 36 Preheating and Inter-run Temperatures ............................................................................................................... 36 Process Applications..............................................................................................................................