The Excalibur Quatuor was first introduced to the public at the 2013 SIHH and still remains the world’s only wristwatch with four balances engineered to deliver unprecedented levels of chronometric precision. We’ve seen it in red gold, in DLC-coated titanium and in monobloc silicon so far, and 2017 will bring us a version in cobalt-chrome alloy.
This may not sound too exciting, but the chemical composition of the case material is by far the least interesting thing about it. That said, if metallurgy is not really your thing, you might want to skip the next paragraph.
The alloy undergoes a patented process known as the Micro-Melt powder metallurgy process. The pre-formed alloy is melted and refined in a furnace under a state of vacuum, then forced through a stream of high-pressure inert gas, which dissipates the melted alloy into extremely fine metal alloy powder of high chemical purity and homogeneity. The powder is further screened to separate it by particle size. The powder is blended according to strict ratios depending on the desired properties of the end result, and subsequently poured into canisters which are subject to hot isostatic pressing. The hot isostatic process reduces porosity and increases density, so the metal powder is a compact solid when retrieved from the canister. After a bit of hot-working, it’s ready to be machined for its final purpose.
Essentially what you’re left with, after this process, is an alloy that is stronger, harder, tougher, more homogenous (and therefore more ductile), higher in purity and with an exceptionally clean microstructure compared to the initial cast alloy. Given all this, it’s much more difficult to machine, but that just means it’s as just as durable as the movement within. The cal. RD101 of the Quatuor has four hearts to stand up to any amount of bashing that you might care to inflict upon it — surely it’s only appropriate that its case can do the same.