Aurumite® Patented by Powell

Summer 1991 issue of the Powell Newsletter

With the unveiling of our Ruby Aurumite® Custom flute this week at the 2014 NFA Convention, we thought it might be a good time to learn more about Aurumite and its history with Powell.  We opened the archives and found that the Verne Q. Powell Flutes Newsletter from the summer of 1991 highlighted Aurumite, describing its formation and noting its patent date and number.  The newsletter states:

On October 9, 1990, U.S. Patent 4,962,007 was assigned to Verne Q. Powell Flutes for "Flute tubing of laminated metal including a bonded layer of precious metal alloy."  This technology was invented and developed at Powell.  The issuance of the patent is recognition of the originality of this technical conception.  It also means that no other flute or headjoint maker can use this technology without obtaining a license from Powell.  To date, no licenses have been issued.

If you are wondering how Aurumite was developed -- and how it is formed -- the newsletter provides more details on the history and process:

For the past four years, Powell has been using a proprietary fusion technology to create unique combinations of precious metal flute tubes.  The idea behind this invention was that the inside layer of metal made more difference in the sound than the outside layer.  The challenge, therefore, was to find a way of concentrating expensive precious metals like gold or platinum on the inside of a sterling silver tube.

Powell's concept was to put a flute tube of one precious metal inside another.  The inner "tube" would be made of a relatively dense and expensive precious metal compared to the other tube.  The patented process accomplishes this by metallurgically bonding sterling silver and 14k gold to each other while each is still in sheet (or flat) form.  The resulting laminated sheet is then cupped and drawn into flute tubing just like most other flute tubes are made.  

The version of this fusion technology which has become most popular over the past four years is Aurumite™ I.  In this form, the inner layer of the tube is Powell's regular 14k gold alloy, and the outer layer is comprised of sterling silver.  Flutists who own Aurumite I flutes or headjoints like the excellent projection of this material combined with a warmth and sweetness normally associated with gold.

Unlike plated flute metals, Powell's Aurumite is work hardened.  It can be filed and polished in the same way as normal flute tubing.  Not only is Aurumite metal hard compared to a plated flute, but the gold layer is approximately 35 times thicker than normal plating.

The "Aurumite I" mentioned in the newsletter excerpt is Powell's current "Aurumite 14k," which is sterling silver on the outside and 14k gold on the inside.  Ruby Aurumite, the newest member of the Aurumite family, is 14k gold on the outside and silver on the inside.  For more information on the new Ruby Aurumite flutes, click here to visit the Ruby Aurumite page on the Powell website.

Powell Aurumite 14k Custom Flute

Powell Ruby Aurumite Custom Flute

Ductility

Signature flutes (all have drawn tone holes).

Recently, a customer inquired as to why he could not buy a Custom Aurumite 14k, 14k white gold, or platinum flute with drawn tone holes.  We had the chance to speak with Powell’s President, Steven Wasser, to find the answer…

Closer view of the Signature flutes.

Mr. Wasser explained that the reason why drawn tone holes were not an option for flutes made from these metals is because of the metals’ ductility.  Ductility is essentially the metal’s capacity to be drawn out into a different shape (without breaking).  If a metal has a high level of ductility, it would have the capacity to withstand the tone hole drawing process.  In this process, Wasser explains “the tubing is pulled out of a small hole in the flute body into a tall ‘chimney’ to form the tone hole.   It is then rolled over and flattened to create the surface for the pad to close against” (from the post Tone Holes - Drawn or Soldered?, May 16, 2012). 

Super close-up on drawn tone holes.

All metals have a ductility level, and both white gold and platinum have reduced ductility – therefore, they do not flow the same way a much more ductile metal like silver would.  Aurumite is comprised of two different metals – one outer layer of silver, and one inner layer of 14k gold.  Silver and gold have differing levels of ductility, and the layers will want to move at different rates (with silver wanting to move faster than gold).   Although a numeric value is not always given for a metal’s ductility, a certain level is needed for the metal to be successfully drawn into tone holes.  Wasser states that a “100% success level is needed,” so if even one tone hole does not form properly in the drawing process, drawn tone holes would not be an option for that particular metal.  In this case, it would be the Aurumite 14k, 14k white gold, and platinum.