1 NATIONAL ACADEMY OF SCIENCES OF UKRAINE COMBINE TECHNOLOGY FOR PRODUCTION OF COAXIAL Cu-Al ELECTRIC CONDUCTORS BY EXPLOSION CLADDING AND DRAWING FOR AIRCRAFT INDUSTRY Dobrushin L.D., Bryzgalin A.G., Shlonskii P.S., Lavrenko I.G., Romashko I.M., Lavrenko I.G., Romashko I.M., Hugo Groeneveld Hugo Groeneveld The E.O. Paton Electric Welding Institute (PWI)

2 1. Title 2. Speaker Dr. Andrey G. Bryzgalin The E.O. Paton Electric Welding Institute (PWI) of NAS of Ukraine Department on Welding, Cutting and Treatment of Metals by Explosion PRODUCTION OF COAXIAL Cu-Al CONDUCTORS COMBINE TECHNOLOGY FOR PRODUCTION OF COAXIAL Cu-Al ELECTRIC CONDUCTORS BY EXPLOSION CLADDING AND DRAWING FOR AIRCRAFT INDUSTRY

3 3. Introduction PRODUCTION OF COAXIAL Cu-Al CONDUCTORS Electric conductors for power supply and control system of aircrafts have to have low weight, high capacity and reliability. Bimetal Cu-Al conductors using explosion cladding and further drawing were investigated for production of such conductors. Technical requirements to Cu-Al conductors are the following: 1. Proper thickness of conductors Cu shell should be constant. 2. Intermetallic compounds at the interface should be absent; 2. Elasticity for 3D formability of conductors should be provided;

4 PRODUCTION OF COAXIAL Cu-Al CONDUCTORS 4. Principal Design and Performance Cu-Al Coaxial Conductor and its Longitudinal Section

5 5. Explosion Cladding & Drawing PRODUCTION OF COAXIAL Cu-Al CONDUCTORS Scheme of Explosion Cladding Equipment for Further Drawing of Clad Cu-Al Rods

6 PRODUCTION OF COAXIAL Cu-Al CONDUCTORS Required quality of Cu-Al interface were provided by: - Lower boundary of explosion welding; - Optimal cladding length of workpieces; - Proper routing of mechanical drawing; - Optimal conditions of post heat treatment. Remark: a standard Cu tubes were used in calculations. 6. Quality Providing Aspects Optimal Geometry of Cu-Al Explosion Clad Rod Ø 26 mm before Further Drawing

7 PRODUCTION OF COAXIAL Cu-Al CONDUCTORS Electrical Conductivity = 0,027 Ohm/m Heat Treat. σ y, MPaσ t, MPa δ, % Interme- tallics °C, 1 H °C, 1 H °C, 40 min Mechanical Properties of Cu-Al Rod

8 Quantity of passed bends: without heat treatment – 3 times after heat treatment – 24 times 8. Bending Test Results PRODUCTION OF COAXIAL Cu-Al CONDUCTORS

9 Developed combine technology of explosion cladding and further drawing provides intermetallic free Cu-Al interface 8. Microstructure of Cu-Al Interface PRODUCTION OF COAXIAL Cu-Al CONDUCTORS

10 9. Semi-Finished Cu-Al Conductors PRODUCTION OF COAXIAL Cu-Al CONDUCTORS PWI is capable to produce by developed combine explosion cladding and drawing technology Cu-Al conductors as a bus-bar of the following parameters:  Dia: 8.0 and 8.8 mm;  Cu Shell thickness: 0.3 mm;  Medium density: 3.6 g/cm3

Finished Cu-Al Conductors PRODUCTION OF COAXIAL Cu-Al CONDUCTORS Typical Cu-Al Shaped Conductors used in Aircraft Industry

Main Conclusions THANKS FOR YOUR ATTENTION ! PRODUCTION OF COAXIAL Cu-Al CONDUCTORS 1.Combine technology for production of coaxial Cu+Al electric conductors by explosion cladding and drawing have been developed and successfully tested. 2.Explosion cladding with further drawing opens possibility to perform cladding at lower limit of the process, what provides high quality interface and service properties of conductors. 3. The developed combine technology is recommended for production of Cu-Al conductors (bus-bars) for power supply and control systems in aircraft and other industries.