I am interested in techniques than can be used to work harden materials apart from hammering. I would like to know some techniques that wouldn’t add any sort of texture, as hammering with a plain metal hammer would result in a hammered texture, which is nice but not what I’m going for. Tumbling doesn’t penetrate the material and lead to any sort of true added hardness. Heat hardening isn’t an option as I’m more interested in using pure metals such as fine silver. I am guessing some method of twisting the material? Maybe hammering and then filing the texture off, but this sounds pretty wasteful.
From what I understand, Fine Silver cannot be work hardened. The surface can be compressed during tumbling, it can be planished, but it does not work harden.
Fine silver can indeed be work hardened. I have rolled an ingot in .999 to wire and it was quite hard, in fact it was close to cracking and yet after annealing it became buttery soft and malleable again. All materials work harden, the atoms arrange themselves in a crystal lattice which is crushed and crushed by working until it can’t handle it anymore and cracks. When we anneal, we re-structure the crystals.
All metals used in jewellery will work harden, and some will age harden. Age hardening occurs by cooling slowly instead of quenching, but only certain alloys exhibit the effect. Work hardening always works and will occur whenever the metal is deformed - bent, drawn, hammered, rolled or twisted. For ear-wires and brooch-pins which have to be soldered, the way I work harden is to make the pin a few millimetres longer than required, bend one end to a right-angle, solder the other end as needed, then use the bent end as a lever to twist the pin back and forth until it feels hard enough, then snip the unwanted bent bit off and tidy up by filing.
ActuallyContinuum silver work hardens better when immediately quenched. Heated to 800F for 40 mins. then quenched immediately It gets almost as hard as !4kt while gold. I ran an experiment kiln hardening Continuum and found it was softer when air cooled than when quenched. The casting also should be quenched to get max hardness. It’s a silver palladium alloy. Quite stable at high temps, no fire scale, fuses beautifully, hardest silver alloy out there. Perfect for clasps, earring wires, and posts when kiln hardened.
Jo