The “Lost art of hardening copper”

[pgk pgkParticipant @pgkpgk17461]

[pgk pgkParticipant @pgkpgk17461]

I just stumbled on this patent when looking for an alternative to work hardening annealed copper – just a curiosity…

This Link
https://patents.google.com/patent/US1359810A/en

From a gentleman who patented his way of hardening copper by heating and covering in powdered glass before quenching.

This Link
file:///C:/Users/cwmfarm/AppData/Local/Temp/nbslettercircular444r1935.pdf

Implying that the first method unknowingly just alloys the copper with it's own oxides?

[Michael GilliganParticipant @michaelgilligan61133]

Excellent find … Thanks

Unfortunately, your second link doesn’t work for me

MichaelG.

.

Edit: __ but this does:

https://nvlpubs.nist.gov/nistpubs/Legacy/LC/nbslettercircular444r1935.pdf

Edited By Michael Gilligan on 19/08/2021 19:23:23

[pgk pgkParticipant @pgkpgk17461]

Sorry 'bout that – will try and be on't ball next time…

[Michael GilliganParticipant @michaelgilligan61133]

No problem … I got good value for my meagre effort

MichaelG.

[Bo’sunParticipant @bosun58570]

Some years ago, on a trip to Egypt, we were told that Egyptian craftsmen used copper for carving rock ( including granite apparently). It seemed a bit far fetched, but might this have been how they managed it? There seems little information out there about how the ancients were able to manipulate rock, so precisely and so much of it.

[Oily RagParticipant @oilyrag]

An interesting 'discovery'! I liked the bit in the NBS letter Circular about the alloying of copper – one of the most difficult materials I have ever had to machine has been CuBe (Copper Beryllium alloy of 1.5% Beryllium) which would blunt a HSS hacksaw in a few strokes and would require the very sharpest carbide to stand a chance of lasting. It has some amazing properties such as a very high capability to dissipate heat allied to a high wear resistance, hence its use as a valve seating material and guides in race ICE engines. Meanwhile Beryllium when alloyed with Aluminium (with small amounts of Nickel, Magnesium, Copper and Titanium) makes an exceptionally strong piston material with exceptionally high strength at elevated temperatures.

The sad aspect of all this is that Metallurgy as a subject has all but disappeared from British University courses, one of the UK's leading establishments was Sheffield's Metallurgy Department which closed a number of years ago.

Martin

[duncan webster 1Participant @duncanwebster1]

I believe lots of tools used down coal mines were made from Beryllium Copper, not because it was better than steel, but it wouldn't create sparks to set off firedamp explosions

[J HancockParticipant @jhancock95746]

Not to forget copper oxide was an early use of a semi-conductor .

[Tim StevensParticipant @timstevens64731]

Ah yes, I remember copper oxide rectifiers. On the early japanese step-throughs and small motor bicycles, they were often fitted below the seat (which had a plywood base in those days). And of course, they earned a reputation as rectum-fryers.

Cheers, Tim

Edited By Tim Stevens on 20/08/2021 17:38:24

[john fletcher 1Participant @johnfletcher1]

Avometers 7 & 8 and most other analogue multimeters had copper oxide rectifiers, which looked like 4 little copper spring in a plastic mount. Never seen a copper oxide on a motor bike, usually a Selenium type on Bantams and Villiers. My Honda 90 had an encapsulated bridge rec, wonderful machines were the 70 & 90. John

[mark costello 1Participant @markcostello1]

I saw a show that said the copper was used as a saw (or lapping) blade to saw the blocks out. Makes sense as saw marks are visible. What is also interesting is that in South America some of the locals said the old timers () had a way of softening the rock to make it conform to the rock below. They said putting some kind of wet plants on the rocks made the rock soft.

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