Like the first Roger Dubuis Excalibur Quatuor replica watch — introduced at SIHH 2014 and featuring the world’s first replica watch case made of silicon — the Quatuor Cobalt MicroMelt is outfitted with Roger Dubuis’s manually wound, 890-part Caliber RD101, whose outstanding technical feature is its four sprung balances with five differentials, arranged concentrically around the movement and positioned on an incline. They are intended to perform the same function as a tourbillon, i.e., eliminating timing errors caused by the effects of gravity on the balance, but to do it better. The four balances give the replica watch an amazingly high frequency of 16 Hz, or 115,200 vph. (That’s 4 Hz times four balances.)
Instead of silicon, however, the new Quatuor — which will be limited to just eight pieces worldwide — uses a high-performance cobalt chrome alloy, produced through the exceedingly rare MicroMelt metallurgical technique, for its 48-mm case, bezel, and crown. All the aesthetic hallmarks of the Excalibur collection — the Roger Dubuis brand’s undisputed flagship — are present, including the notched bezel, graphically dynamic curving Roman numerals, and triple lugs integrated into the case and strap.
The MicroMelt process, which is used chiefly in aeronautics and astronomy, involves melting and atomizing the molten alloy into a fine powder by subjecting it to a high-pressure stream of gas using a dedicated vacuum induction melting gas atomization unit. This powder is then blended and screened to a controlled diameter, poured into canisters that are sealed and subjected to hot isotsatic pressing to achieve full density, hot-worked to produce hot-rolled bars, and finally processed to finished size. Unlike many other such processes, this technique enables the creation of new, specific alloys, including ones blending metals with non-metals, while also imparting greater porosity and stability.
The resulting alloy used for the replica watch case, according to Roger Dubuis Men’s Replica, is 100 percent biocompatible; very corrosion-resistant due to a spontaneous formation during the process of a passive, protective film; and extra durable thanks to the multiphase structure and the precipitation of carbides. It also has a distinctive shine that contrasts appealingly with the blue PVD-coated elements of the movement and openworked dial, including the barrel cage and bridges; the speedometer-style minute track with contrasting red markers; and the flange with stylized, rhodium-plated Roman-numeral hour markers. The hour and minute hands are in white gold, with red tips filled with Super-LumiNova. A power-reserve indicator, also bearing blue highlights, appears at 9 o’clock.