Black makes a bold statement on the wrist. In creating a completely black watch, IWC Schaffhausen developed a dark matte composite, demonstrating its expertise in fabricating high-tech materials.
After the world's first wristwatches with cases in black zirconium ceramic, black boron carbide ceramic and brown silicon nitride ceramic, the Swiss maison debuted the first-ever timepiece with a Ceratanium case last month.
Aquatimer Perpetual Calendar Digital Date-Month Edition 50 Years Aquatimer is housed in the matte black case made with the groundbreaking titanium alloy that took more than five years of development.
A special manufacturing process gives the metal a black, ceramic-like surface while combining titanium's and ceramic's advantages.
"Ceratanium is as light and tough as titanium but as hard and scratch-resistant as ceramic. Other compelling features are its skin-friendliness and high resistance to corrosion," said Lorenz Brunner, IWC's head of materials development.
Most watch manufacturers use PVD coating for black cases, Brunner noted, by placing the metal in a vacuum chamber for an ultra-thin diamond-like carbon (DLC) coating.
"This type of coating is a little like the shell of an egg: it can chip or flake off if the watch is hit or bumped. In the light of our extensive experience in case manufacture and hardening processes, IWC decided not to use this particular process," he said.
Made specially for the Swiss luxury brand, the alloy in the form of round bars are shaped by machine and subsequently placed in an oven. Oxygen is diffused through the material, leading to a "phase transformation" by which the metal's surface is ceramicised.
"We make all the case components from Ceratanium, milling, turning, drilling and polishing them until they've reached their final shape. Only then do the parts go into the oven," Brunner said. "The special composition of the titanium alloy initiates a diffusion process and the surface of the material is transformed into ceramic. But the thing is: it isn't a coating. It's a bit like a loaf of bread: during baking, bread develops a crust that's difficult to remove afterwards."
The process gives Ceratanium not only typical ceramic properties but the striking matte black colour boasted by the Aquatimer Perpetual Calendar Digital Date-Month Edition "50 Years Aquatimer".
The innovative material was used for making not only the case but also the clasp, crown and push-buttons. The black colour scheme extends to the dial, some components of the IWC-manufactured calibre 89802, such as the self-winding system's rotor, as well as the rubber strap.
Water-resistant up to 10 bar, the timepiece, like all Aquatimer models, features the external/internal rotating bezel for setting dive time.
The IWC SafeDive system ensures that the internal rotating bezel can only be adjusted when the external one is rotated counter-clockwise. As a result, even if the external bezel is accidentally moved, zero hour -- the time at which the diver can return to the surface without the need for decompression stops -- cannot be exceeded.
Other technical features include a digital perpetual calendar, displaying the date and month in large numerals in the style of a digital watch, and automatically recognising different month lengths and leap years. The chronograph with flyback function displays stop times, combined in a totaliser at 12 o'clock.
Available at IWC boutiques, the special edition is available in 50 pieces to mark five decades of the sporty diver's watch.
