Heavy press magnesium forgings for Luftwaffe aircraft

[historygeek2021]

I've seen anecdotal information on various websites claiming that Germany used heavy presses to forge magnesium components for their aircraft. These magnesium forgings were used to attach the engine to the airframe and took the Allies far longer to manufacture because only Germany had heavy presses that could forge them.

Does anyone have any reliable sources of information about this?

[MikeMeech]

I've seen anecdotal information on various websites claiming that Germany used heavy presses to forge magnesium components for their aircraft. These magnesium forgings were used to attach the engine to the airframe and took the Allies far longer to manufacture because only Germany had heavy presses that could forge them.

Does anyone have any reliable sources of information about this?

Hi

This may not directly answer your question but the information might help to judge the industrial situation in Germany. First source 'German Aircraft Industry and Production 1933-1945', by Vajda & Dancey, reference Magnesium, page 127:

WW2RAFsqnest059.jpg (75.9 KiB) Viewed 8069 times

Page 128-129 on Machine Tools:

WW2RAFsqnest060.jpg (62.14 KiB) Viewed 8069 times

Second source NID's 'Germany Volume III, Economic Geography', November 1944 edition, show the pre-war Magnesium situation:

And the Machine Tool industry:

Considering German Machine Tools were more 'general purpose' than the USA I would expect the USA, at least, would be able to produce similar equipment, as probably could the British, if required.

Mike

[historygeek2021]

Thanks Mike. Very helpful.

[Peter89]

What we call aluminium was actually duraluminium thus containing Mg and Cu as well. Using "pure Mg" was rather rare or even dangerous. Most metals keenly oxidize or even prone to high intensity ignition.

Ferenc Vajda's book is full of infos, but they are not really accurate and could rarely be traced back to the source. For example, he gives wrong numbers for aluminium production / useage, ie. confusing primary and total production. But this is hard work to cross-check.

[T. A. Gardner]

In the US, magnesium was used widely in some aircraft manufacturing to include large portions of the airframe and skin. Northrup in particular, used magnesium in aircraft they built for such purposes.

Pratt & Whitney used magnesium castings--I don't know if they used forgings or not though--in various components of their engines like the gear casings to lighten the weight too.

[Peter89]

In the US, magnesium was used widely in some aircraft manufacturing to include large portions of the airframe and skin. Northrup in particular, used magnesium in aircraft they built for such purposes.

Pratt & Whitney used magnesium castings--I don't know if they used forgings or not though--in various components of their engines like the gear casings to lighten the weight too.

Pure magnesium, and not alloys?

[Seppo Koivisto]

The AS21 alloy used for VW Beetle engine blocks was 96.7% magnesium.

The magnesium engine bearers and the engine reduction casing of this Bf 109 found in a lake had dissolved in the water. https://www.key.aero/article/messerschmitt-bf-109g

The Soviets took German presses and the US had to make their own. https://www.theatlantic.com/magazine/ar ... nt/308886/


https://digital.sciencehistory.org/works/rdwoz86

[T. A. Gardner]

In the US, magnesium was used widely in some aircraft manufacturing to include large portions of the airframe and skin. Northrup in particular, used magnesium in aircraft they built for such purposes.

Pratt & Whitney used magnesium castings--I don't know if they used forgings or not though--in various components of their engines like the gear casings to lighten the weight too.

Pure magnesium, and not alloys?

Alloys. Northrup made virtually whole airframes from magnesium alloys. Both the XP-56 (Black Bullet) and XP-79 airframes were made almost entirely from magnesium alloys. On the XP-79 plate up to as much as a quarter inch or more was used in some areas doubling as armor.

[Peter89]

In the US, magnesium was used widely in some aircraft manufacturing to include large portions of the airframe and skin. Northrup in particular, used magnesium in aircraft they built for such purposes.

Pratt & Whitney used magnesium castings--I don't know if they used forgings or not though--in various components of their engines like the gear casings to lighten the weight too.

Pure magnesium, and not alloys?

Alloys. Northrup made virtually whole airframes from magnesium alloys. Both the XP-56 (Black Bullet) and XP-79 airframes were made almost entirely from magnesium alloys. On the XP-79 plate up to as much as a quarter inch or more was used in some areas doubling as armor.

Nice infos, thanks!

[T. A. Gardner]

Northrup also invented and perfected a means of welding magnesium alloy metals in 1944 called the Heliarc process. Today it's commonly referred to as TIG welding. Engineer Russell Meredith was the inventor. This variant of arc welding allowed Northrup to build an airframe that was welded together rather than riveted, saving production time and weight in the final airframe.

[MikeMeech]

Northrup also invented and perfected a means of welding magnesium alloy metals in 1944 called the Heliarc process. Today it's commonly referred to as TIG welding. Engineer Russell Meredith was the inventor. This variant of arc welding allowed Northrup to build an airframe that was welded together rather than riveted, saving production time and weight in the final airframe.

Hi

The 1943 book 'Airframe Construction and Repair' by John T Henshaw, Pitman & Sons, mentions the casting and welding of Magnesium Alloy:

Another wartime book 'Aeronautical Engineering, A practical guide for everyone connected with the Aircraft Industry', edited by R A Beaumont, Odhams Press Limited, has mention of the pre-war D.H. 'Gipsy-Twelve' engine using a magnesium alloy casting:

The book 'Internal Combustion Engines Illustrated', Odhams Press Limited reprinted 1947, mentions the use of magnesium alloys in engines:

I hope that is of interest.

Mike

[MikeMeech]

Hi
The 1937 book 'Metal Aircraft Construction' by M Langley, Pitman & Sons Ltd, has a bit of information on the use of Magnesium:

I hope that is useful.

Mike

[MikeMeech]

Hi

The 1935 book, 'Complete Book of Aviation' compiled by Sqn-Ldr C G Burge, Pitman & Sons, Ltd, has mention of the (potential) use of Magnesium alloys:

Also from the late 1930s (part work) 'Aero Engineering, Volume II Production' editor Sqn-Ldr H Nelson, George Newnes Limited, has some mention:

Also use in the DH 'Gypsy Six' crankcase and top cover DTD 281:

Mike

[Peter89]

Hi

Extremely nice infos, thanks!

So far I have been able to conclude that magnesium alloys were used only in specific instances where its low specific gravity was required to a great extent. However, producing 1 kg of magnesium required about cca. 90 kWh of energy while producing 1 kg of aluminium required cca. 20 kWh.

[historygeek2021]

The AS21 alloy used for VW Beetle engine blocks was 96.7% magnesium.

The magnesium engine bearers and the engine reduction casing of this Bf 109 found in a lake had dissolved in the water. https://www.key.aero/article/messerschmitt-bf-109g

The Soviets took German presses and the US had to make their own. https://www.theatlantic.com/magazine/ar ... nt/308886/


https://digital.sciencehistory.org/works/rdwoz86

Thanks. This is what I was interested in. It's mentioned briefly at 0:40 in this video, which says that Germany could quickly forge magnesium components for their aircraft with their heavy presses, whereas the allies had to spend more man hours machining the same parts.

https://www.youtube.com/watch?v=hpgK51w6uhk