How to Solder Gold & Silver Without Heat

Experienced jewelers and manufacturers know that typical "cold soldering" is more accurately described as "resistance soldering." Cold soldering tools, like the popular ColdHeat Soldering Pen, have a split tip with electric current running through each point. When the tips are touched to solder, the probes and the solder heat up very quickly because of their resistance to the current passing through them. Lifting the tips away from the solder breaks the circuit, and everything quickly cools.
   
Now, what if you could use a similar technique on any metal - even ones with very high melting points like gold? Materials scientists at Iowa State University may have just revolutionized the manufacturing industry by developing a soldering method that requires no heat or electricity. It works by forming a shell around microscopic metal droplets and keeping them in a liquid state - even when their surroundings are cooler than their melting temperature - until the shell is ruptured, causing the metal to flow and solidify, like solder.

These droplets are made possible with supercooling - the process of lowering the temperature of a liquid below its freezing point without it becoming a solid. When a liquid falls below its freezing point, it begins to crystalize in the presence of a "seed crystal" or nucleation site, around which a crystal structure can form, creating a solid - almost like how synthetic sapphires are made. Without this seed, the liquid's atomic structure cannot crystalize and become a solid - even if the temperature continues to fall below the freezing point.

Solid metals have a crystalline structure, so melted metal is subject to the physics of supercooling. The researchers at ISU created the above mentioned droplets by whipping molten metal into a froth, then allowing it to cool gradually. Oxygen in the froth causes the very outsides of droplets to form a thin metal oxide shell. This oxide reacts with acetic acid, forming a smooth oxide-acetate shell that allows the core to stay liquid as it cools. This ultrathin shell prevents the liquid metal from coming in contact with nucleation sites needed to trigger solidification. Rupturing the shells causes the liquid to flow and immediately solidify, bonding surfaces together - kind of like a water balloon filed with super glue. In a demonstration, the researchers used the technique to solder a gold wire to a sheet of gold film, repair holes in silver film and bond sheets of foil together.

Lead researcher, Martin Thuo, has already formed a start-up company, Safi-Tech, to commercialize this technology. Not only does it have the potential to make jewelry repairs easier, it could also revolutionize metal repair, metal casting, and even 3D printing. Perhaps in the future, we’ll be selling these droplets alongside our selection of casting grains.


Platinum-Group Metal Used in Alternative Energy Breakthrough

In alternative energy research, converting carbon dioxide into methane to use as methanol fuel is nothing new. However, new research from the University of Southern California has found a way to make this reaction happen faster and more easily by using a "cousin" of platinum - ruthenium.
   
The biggest challenge for scientists trying to create an efficient carbon dioxide-to-methanol conversion process is finding a homogeneous catalyst that can withstand the high-temperatures of the process without breaking down too quickly. To be homogenous, the catalyst must be the same allotrope as the CO2 and hydrogen atoms it reacts with - which is essential for producing methanol at a worthwhile rate.

According to the researchers, the solution was to use a special ruthenium phosphine complex. While the idea of using ruthenium has evaded scientists for some time, it may be more obvious to jewelers and precious metal refiners. Compared to pure platinum or platinum-iridium alloy, platinum-ruthenium alloy is extremely tough stuff that's perfect for crafting long lasting jewelry or for industrial-grade parts that need to work in extreme environments. In fact, the most common casting grain we sell here at MGS is 95% platinum alloyed with 5% ruthenium.

This breakthrough in chemistry has many potential benefits. Not only is methanol a useful fuel source, it’s also used to create more complex compounds that make the manufacturing world go ‘round, such as ethylene and propylene, which are in turn used to make plastics and other products. Additionally, being able to convert at least some of the CO2 that humans regularly add to the atmosphere could be very beneficial for the environment.

Luxembourg's Plans to Enter the Asteroid Mining Industry

The government of Luxembourg announced a new series of initiatives earlier this year to establish the country as a major player in the bourgeoning industry of asteroid mining. This makes Luxembourg the second country (the first being the United States) to take definitive steps toward developing a legal and regulatory framework for the industry.
       
To kick off their initiatives, Luxembourg launched SpaceResources.lu. According to a press release from the government, the budget allocated to SpaceResources.lu will be part of the national space budget that will be defined in the frame of the preparation of the Luxembourg contribution to the next multiannual budget of the European Space Agency to be decided in December 2016. Part of their plans include defining the property rights for private operators who obtain non-living resources from outer space – similar to the Space Resource Exploration and Utilization Act outlined by US Congress.

Unlike the US however, Luxembourg has expressed interest in directly investing in private asteroid mining companies and relevant R&D projects. Chris Lewicki, President and CEO of Planetary Resources likes the sound of that, saying in a statement “Planetary Resources looks forward to working with Luxembourg.”

It may sound strange for a small European country to take a serious interest in such new (and expensive) technology and research, but the country is already somewhat well established in the field as the home to 30+ year old SES – a communications satellite owner and operator with a fleet of more than 50 active and occasional use geostationary communications satellites. That kind of connection could prove useful when scouting for mineable asteroids in the future.