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<p>[QUOTE=&quot;Tom Maringer, post: 182713, member: 7033&quot;]<b>The &quot;weird&quot; metals</b></p><p><br /></p><p>The more unusual metals I&#039;ve worked with have included Titanium, Niobium, Tantalum, Hafnium, and high-purity Iron. They have some unusual properties. Pure iron is a completely different animal than steel... which is an alloy of iron with carbon. The pure iron I was getting had a carbon content less than 0.002%. At that level iron is a little softer than copper, and does not work harden hardly at all. It will just keep working and working, almost like pure gold. The other &#039;transition&quot; metals tend to be harder to strike than copper or silver... and a bit &#039;smeary&#039;... that is... they tend to leave smears of metal on the dies if there is too much flow across the surface. For this reason they are best used on low-relief pieces with minimal flow. Also the hardness of the metals will break down or wear dies two to three times as fast as usual... so I have generally done only short runs with them. They are a bit costly and impossible to weld or smelt. So any scraps are not recyclable usiung ordinary methods.&nbsp; Pure iron is awesome stuff... but terribly hard to get and costs three four times what copper does. The mill that used to make it in Germany has apparently closed, and I managed to get a few pounds of the last stuff... I used it for my &quot;Iron Crown of Morgoth&quot; It takes detail extremely well and looks really cool when &quot;blued&quot; a deep black. The only problem is that people expect iron to be cheap. Iron is NOT the same thing as steel, and I sometimes get tired of explaining it. Titanium is the easiest to get, and very light, but the finish on the plates of the high-purity grade-1 is a terrible orange-peel. Unless you have them ground flat (very expensive) you have to coarse-tumble the blanks for WEEKS to get them smooth enough to strike, and even the high-purity grade is hard on dies. Hafnium is even harder to strike than titanium... but it is denser than silver and takes GORGEOUS anodization colors, especially green. It&#039;s particularly interesting stuff because of its nuclear properties (it is the best neutron absorber of all... and makes great radiation armor) Tantalum is a very dark gray metal and nearly as dense as gold (black-gold?). It runs three to four times the price of silver... and tough to locate at any price, but has the deepest blues and purples in its anodization range. Niobium is perhaps the most interesting and forgiving of all these transition metals. It&#039;s about the same density and hardness as copper, coins pretty well and has a wide range of nice anodization colors available. The problem with niobium is availability, dimension, and price. Most of the stuff is 0.040&quot; or thinner... which is pushing the lower limits of what we can use for minting and it costs about the same as silver... but you can&#039;t recycle the blanking scraps, so there is lots of waste. All of these metals have the property of extremely high melting points and are highly reactive with oxygen at elevated temperatures. I&#039;ve made buttons and lapel pins out of many of my coin designs using copper brass and silver... but in niobium the stick-pin idea would be tough because of its properties... you&#039;d probaly have to use a laser or perhaps a spark-welder to put a post on the back. It might be possible to make some sort of mechanical connection with rivets or pins.[/QUOTE]</p><p><br /></p>

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