Aluminium work hardens and as working is involved in producing sheet and bar etc it will be at least fairly hard. There are various grades as well. Spec may mention annealing temperatures.
The proper way to anneal is with a furnace set to the correct temperature but there is a dodge that can be used for thinner stuff using a plumbers torch. One with a large flame is the best option, The basic idea is to cover the aluminium with something that changes colour at the right temperature as just continuing to heat will melt it.
2 items are used in much the same way. A sharpy or a bar of hand soap. Mark zigzags etc all over etc with either.The sharpy will burn off. The soap will go black. The sharpy marks will disappear. Do it slowly and maybe put a little more heat in when this happens / try to hold it at that temperature. I've used soap.
Another way and likely to be preferable for smaller parts. I did a sizeable sheet. Coat it with soot from a candle and burn that off.
In all cases slowly and heating evenly.
Quenching in water as soon as it's hot enough gets mentioned. With my soap and sheet it wouldn't be possible to do that evenly. If I tried soot I'd try a couple of samples one with it and one without and compare.
The proper way to anneal is with a furnace set to the correct temperature but there is a dodge that can be used for thinner stuff using a plumbers torch. One with a large flame is the best option, The basic idea is to cover the aluminium with something that changes colour at the right temperature as just continuing to heat will melt it.
2 items are used in much the same way. A sharpy or a bar of hand soap. Mark zigzags etc all over etc with either.The sharpy will burn off. The soap will go black. The sharpy marks will disappear. Do it slowly and maybe put a little more heat in when this happens / try to hold it at that temperature. I've used soap.
Another way and likely to be preferable for smaller parts. I did a sizeable sheet. Coat it with soot from a candle and burn that off.
In all cases slowly and heating evenly.
Quenching in water as soon as it's hot enough gets mentioned. With my soap and sheet it wouldn't be possible to do that evenly. If I tried soot I'd try a couple of samples one with it and one without and compare.
That kinda depends on the actual use.
If the metal needs strength then yes an alloy is the way to go but if you need to prioritize electrical conductivity you really want a pure metal.
For example pure gold is a very good conductor and silver the best but if you alloy them with each other the resulting material has a conductivity well below either pure silver or gold with a 50/50 mix being the worst.
Had a conversation with Chris Sörensen from Seas yesterday and he did not think that Beryllium is going to be a feasible alternative for tweeter diaphragms for long.
Price and raw material shortage with ridiculous delivery times being the main reasons why. The industry is increasingly looking at Textreme prepreg carbon weave (from the Swedish company Oxeon) as a replacement and one of the leading suppliers of diaphragms ,Dr. Kurt Müller, are now offering these to the OEM market at scale.
Price and raw material shortage with ridiculous delivery times being the main reasons why. The industry is increasingly looking at Textreme prepreg carbon weave (from the Swedish company Oxeon) as a replacement and one of the leading suppliers of diaphragms ,Dr. Kurt Müller, are now offering these to the OEM market at scale.
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Yes, copper is an example of this. But good luck in finding a 24 carat gold plated connector f.i. Pure 999 silver is almost useless for anything other than jewelry because it is extremely soft and is subject to severe oxidation in air.
worth pointing out that very low levels of impurity will trash the conductivity of silver and copper.
https://www.copper.org/applications/industrial/DesignGuide/selection/conductalloy02.html
https://en.wikipedia.org/wiki/International_Annealed_Copper_Standard
Particularly that sulpher is so disastrous makes plating conductive material with conductivity approaching bulk a dark art. There are companies that can plate plastic waveguide with low surface roughness silver for minimum loss and weight for space applications but the methods are quite secret.
IMO Be is dead as a tweeter diaphragm material, the price keeps going up and TiN, Textreme and the technology in the AXI2050 show alternatives.
If only silver would oxidize easily but it doesn't.
Silver oxide is not a good conductor but a decent one. It is also practically inert which is why they make switches from it which are used in very corrosive environments. The tarnish you get on silver is silver sulphate (sulphide?) which is a semi-conductor.
Silver oxide is not a good conductor but a decent one. It is also practically inert which is why they make switches from it which are used in very corrosive environments. The tarnish you get on silver is silver sulphate (sulphide?) which is a semi-conductor.
Beryllium has good mechanical properties even unalloyed.
https://hificompass.com/sites/defau...he whole truth about beryllium diaphragms.pdf
https://forums.prosoundweb.com/index.php?topic=93016.0