In some cases you may get properties between the 2 metals, but in other cases you may get intermetallics or phase separation with totally different properties. The alloy's final properties depend a lot on the atomic bonding between your elements. It's like saying "sodium is explosive, and chlorine is toxic, so mixing them together will make the ultimate lethal chemical!" This statement is also not necessarily true. If a metal is too brittle, can't you alloy it with something more malleable? So it's really hard to think of a reason to use this instead of another metal, except in the jewelry usecase. Also the solidus will drop to 1063C even at 99% W and 1% Au. So yes, you could possibly make something sword-like out of a W-Au alloy, but it would probably be worse than steel in every way (strength, ductility, cost, density). Looks like this is malleable, but it's mostly used in jewelry to make a different color of gold which doesn't trigger a nickel allergy. I did find a patent for a gold-tungsten alloy. (If alloying the 2 metals produced a straight line between the melting points, you'd expect only 150C lower). Those metals actually alloy very well together, but 90% W and 10% V will have a melting point about 300C lower than pure W. For example, someone earlier brought up whether it was possible to alloy W and V. And alloying will dramatically reduce that melting point. So it's just hard to think of a good application where you would want tungsten besides for its high melting point. Tungsten's high melting point is frequently annoying for machining as well. Even if you're not in an airplane or whatever, heavier materials cost more to transport etc, and therefore drive up the cost. There is, for example, a kind of superalloy which is roughly Co-9Al-9W.Īlso consider that tungsten is dense, which is usually a bad thing. ![]() If you're looking for mechanical properties at high temperature, superalloys are your best bet. You mention W being bad because it's brittle-but if mechanical properties are important, it's hard to beat steel or aluminum. There are many situations in which is makes sense to alloy things with tungsten-you just have to consider whether a tungsten alloy is still the best available material. Alloying will decrease the melting point drastically. Well, the main reason to use tungsten for things is because it has a super high melting point. Why do you want a tungsten sword, heat resistance? This means you would have to cast it, which is difficult due to the high melting point and will give poor properties. ![]() I doubt you could even forge a refractory alloy into the shape of a sword without it cracking apart. In general, you want to avoid refractory elements if ductility is important to the application. FCC elements like gold might be added to intentionally create a useful second phase, but not to increase ductility. However, these works are looking to take the ductility of tungsten from "abysmal" to "barely acceptable." I would not call these alloys ductile. Most of the research I see involving making tungsten more ductile involves other elements in the "9-block" of refractory elements (Ti, V, Cr, Zr, Nb, Mo, Hf, Ta, W) and other refractory elements nearby on the periodic table. Cu-W is commonly used to study various solidification processes due to how easily the two elements separate and how easy it is to distinguish the two phases with various techniques. You will get more of a composite than an alloy. Tungsten and noble metals are one of the prototypical examples of insoluble systems. You won't induce ductility by alloying with Au.
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