Kynal

Brand name for aluminum alloys developed and produced by Imperial Chemical Industries

Kynal was a brand name for a series of aluminium alloys developed and originally produced by the British chemical manufacturer Imperial Chemical Industries (ICI).[1] The name was derived from Kynoch, an existing ICI trademark for ammunition, and aluminium. It was largely used as substitute for Alclad, a popular corrosion-resistant aluminium alloy.

ICI produced Kynal in quantity at a facility in Waunarlwydd, outside Swansea. The material was extensively used by the British aviation industry during the Second World War, being recognised as a strategic resource. Numerous variations upon the material were devised by ICI around this time. During the 1950s, British Railways became a key consumer of Kynal, using the material on numerous members of its new fleet of diesel traction, including the first generation diesel multiple units (DMUs). By the twenty-first century, the material was largely considered to be obsolete, while the Waunarlwydd chemical works was permanently closed during the 2000s.

## History

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A key facility involved in the production of Kynal was the Ministry of Aircraft Production's factory at Waunarlwydd,[2] near Swansea. ICI built and operated the plant on the government's behalf.[3] Functionally, Kynal was similar to, and could be a substitute for, Alclad.[4] Applications included various forged items, including pipework, vessels, and heat exchangers, as well as fuselage elements of aircraft.[5][6] By 1938, the material was being producing at a very high volume as a consequence of the European powers having entered a period of rearmament around the time of Munich crisis, which led into the Second World War.[7]

During the postwar era, Kynal continued to hold its strategic importance.[8] The material proliferated throughout British engineering throughout the 1950s and 1960s; it began to be used in the frames of road vehicles during the mid 1950s.[9] Kynal was used extensively for British Railways' modernisation of the 1950s, specifically in the construction of the publicly-owned organisation's new diesel fleet.[10] The majority of the 'lightweight' diesel multiple units (DMUs) featured the material.[11] Around the same era, the company was also involved in studies into the use of Kynal as a roofing material.[12]

By the twenty-first century, Kynal was largely considered to be obsolete as a material.[13] During the 2000s, the original Waunarlwydd plant, which was by then owned by Alcoa, was closed down.[14][15] Despite this, research efforts into fields such as battery technology have involved the use of Kynal.[16]

## Table

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| Al | Cu | Mg | Si | Mn | Ni | Zn | Others |

|
|
|
|
|
|
|
|
|

| %  |  |
Kynal P5  | ≥99.5  |  | Pure aluminium [17]
Kynal P10  | ≥99
| Aluminium–silicon alloys |
Kynal PA15  |  |  | 12  |  | Brazing wire [18][19]
Kynal PA16  |  | 5
Kynal PA17  |  | 5
| Aluminium–manganese alloys |
Kynal PA19  |  |  | 1.25  |  | [20]
| Aluminium–magnesium alloys |
Kynal M35/1  |  |  | 2  |  | [21]
Kynal M35/2  |  | 3
Kynal M36  |  | 5
Kynal M37  |  | 7
| Aluminium–magnesium–silicon alloys |
Kynal M39/1  |  |  | 0.7 | 0.5  |  | [22]
Kynal M39/2  |  | 0.7 | 1
| Aluminium–copper alloys |
Kynal 90  |  | 2.2 | 0.3  |  | [23]
Kynal C65  |  | 4 | 0.6 |  | 0.5  |  | [23]
Kynal C66  |  | 4.4 | 0.6 | 0.7 | 0.6
Kynal C67  |  | 4.4 | 0.6 | 0.7 | 0.6
Kynal C69  |  | 1 | 1 |  |  | [22]
| Nickel–aluminium alloys |
Kynal Y88  |  | 2.6 | 1 | 1  |  | 1  |  | 0.1% Ti | [23]
Kynal Y92  |  | 4 | 1.5 |  | 2 |
| Aluminium–zinc alloys |
Kynal Z93  |  | 0.4 | 2.7 |  |  |  | 5.3 |  | [24]
Kynal-Core C65A  |  | Pure aluminium-clad forms of the corresponding alloys [25]
Kynal-Core C66A
Kynal-Core C67A
Kynal-Core C68A
Kynal-Core Z93A

## See also

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* Kycube, a similarly named series of copper beryllium alloys produced by IMI.

## References

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### Citations

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1. ^ "ICI Metals Division". Grace's Guide.
2. ^ 51°38′41″N 4°01′16″W﻿ / ﻿51.644727°N 4.021163°W﻿ / 51.644727; -4.021163
3. ^ "ICI Metal Works; Alcoa Aluminium Factory, Waunarlwydd, Gowerton". Coflein.
4. ^ Ross 2013, p. 50.
5. ^ J. H. Argyris; S. Kelsey (1 May 1959). "The Analysis of Fuselages of Arbitrary Cross-section and Taper: A DSIR Sponsored Research Programme on the Development and Application of the Matrix Force Method and the Digital Computer". Aircraft Engineering and Aerospace Technology. 31 (5): 133–143\. doi:10.1108/eb033113. ISSN 0002-2667.
6. ^ "Curtailing Corrosion in Chemical and Petroleum Engineering". Anti-Corrosion Methods and Materials. 5 (6): 195–196\. 1 August 1958. doi:10.1108/eb019457. ISSN 0003-5599.
7. ^ "ICI Advertisement". Flight. 9 June 1938. p. 14.
8. ^ "The British Light-alloy Industry". Flight. 10 June 1955. pp. 808–811.
9. ^ "Kynal lightens". The Automobile Engineer. 1956. p. 125.
10. ^ Carter, R. S. (1963). "North British Locomotive Co. diesel-hydraulic B-B Type 2 (British Rail Class 22)". British Railways Main-Line Diesels. Ian Allan Publishing. pp. 28–29.
11. ^ "Going Ahead with 'Kynal'". Grace's Guide.
12. ^ Kynal, p. 173, at Google Books
13. ^ Ross 2013, pp. 9, 50.
14. ^ "Jobs cut at metal plant". BBC News. 21 January 2003.
15. ^ "298 jobs to go as factory shuts". BBC News. 21 November 2006.
16. ^ "JP3363910B2: Non-aqueous thin battery". Google =. 1998.
17. ^ Metallic Materials Specification, p. 9.
18. ^ Metallic Materials Specification, p. 17.
19. ^ 'Kynal' Solders and 'Kynal' Flux for Soldering Aluminium. ICI. 1953.
20. ^ Metallic Materials Specification, p. 12.
21. ^ Metallic Materials Specification, p. 26.
22. ^ a b Metallic Materials Specification, p. 34.
23. ^ a b c Metallic Materials Specification, p. 41.
24. ^ Metallic Materials Specification, p. 47.
25. ^ Metallic Materials Specification, p. 50.

### Bibliography

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* Ross, R. B. (2013). Metallic Materials Specification Handbook (4 ed.). Springer Science & Business Media. ISBN 9781461534822.
* Frick, John P., ed. (2000). Woldman's Engineering Alloys. Materials data series. ASM International. pp. 667–668\. ISBN 9780871706911.

## External links

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* AIDS FOR THE CORROSION ENGINEER via emerald.com