Explanation in easy terms for beginners: Steel hardening: Heating it will change the inner structure from one state to an other (cubed lettice structure will change inside) --> suddenly quenching it will cool the steel rapidly down without giving it´s inner structure enough time to change back again too it´s normal room temp state. This creating inner stress and making it harder. To release the stress yo ucan heat up the material again to about 500°C and let it cool down slowly which will change some but not all structure and release acess stress thus making the material still hard but not brittle. Aluminium hardening: Heating it will relax the material and alloy components like copper can move freely (495°C-505°C with the help of a candle you can reach this temp without melting the part), all the alloy contents will be the same roughly everywhere within the metal --> quenching it will not change that, however the metal structure will now start to change at room temp. The alloys want to create small islands and will clump together and thus hardening the material You will be able to notice a difference already after minutes. It´s full strength will be reached in about 4 days. You can speed up the process by warming the part, simply put it in an oven at 100°C or so for a while. The colder the temp the less the atoms can move. In aircraft design the metal will be cooled down to below freezing ca. -20°C, to prevent it from hardening too much before it can be riveted.

Currently studying Material Science in my final year Physics degree, this has helped and made a lot of sense especially when you talked about Work hardening. Now the theory makes sense with practical

@backyardfoundry

2 ай бұрын

Glad I could be of assistance! Id love to hear your input on future videos, as I am studying chemistry, not material science.

precipitation hardening isn't age hardening, they are both different steps in the actual hardening. Basically it's like steel, but the opposite. when you quench steel it hardens, and you heat it up to disperse the martensite and have a more souple and flexible structure, but in a lot of non ferrous metals, quenching won't really harden the metal (quenching is precipitation hardening btw, beacause the alloying elements are expelled from the solution and form the martensite), but then heating it back up decomposes the martensite, and oddly enough, it's the decomposed martensite that actually becomes harder and stronger.

@sierraecho884

Жыл бұрын

technically correct however AL does not create any martensite. It´s a little different in AL.

@jeanladoire4141

Жыл бұрын

@@sierraecho884 oh okay i'm mostly working with aluminum nickel bronze, and they make martensite

@sierraecho884

Жыл бұрын

@@jeanladoire4141 Probably because there trace amounts of Fe as well. What I found online is this: " ...The CuAlNiFe group reacts in a similar manner to alloyed tool steels in respect to heat treatment procedures with martensite being formed when components are water quenched from elevated temperatures within a typical range 900-1050ºC. As with steels, the nickel aluminium bronze once quenched can be tempered to improve ductility whilst still retaining high tensile strength and hardnes..." generally speaking Al does not do therefore it hardens by age hardening primarily. What parts do you make out of this alloy ? What´s it used for ? If I may ask.

@jeanladoire4141

Жыл бұрын

@@sierraecho884 i indeed work with cualnife, cual10ni5fe4 mainly, and it's all three metals that form different crystals that constitute the martensite, basically they fall out from solution and form the actual martensite (basically copper/iron crystals, copper/aluminum and copper/nickel). I'm a bladesmith, and i forge blades from cual bronze. It doesn't make very hard blades, actually they are both softer than steel, and more brittle, beacause i'm pushing the temper to its hardest to try to get a few more rockwells from it (i'm at about 30 i'd say, tho i've never measured it accurately). However it does make beautiful golden/brown blades that don't rust. It also holds a shaving sharp edge half decently, but i only make table knives or low intensity use blades from it (mainly for the esthetics, not the performance of course). I'd use a san mai of martensitic stainless steel and a core of very high carbon steel for the edge for cooking knives with actually good performance. But don't underestimate non metals for blades, more humans have died under the blows of bronze blades than under steel or bullets. It will hold an edge, just not for that long, and it needs frequent honing on a stone.

@sierraecho884

Жыл бұрын

@@jeanladoire4141 I see, nice. Very interesting. You surely meant non ferrous metals. Those were THE weapons in bronze age. Of course those are dangerous.