When diving with oxygen tanks began to gain popularity, IWC introduced the first Aquatimer in 1967. This diver’s watch, water-resistant to 200 metres, had an internal rotating bezel for setting the dive time. In 2017 IWC celebrates the 50th anniversary of the Aquatimer family with the world’s first watch with a case made of Ceratanium®.

The Aquatimer Perpetual Calendar Digital Date-Month Edition “50 Years Aquatimer” (Ref. IW379403) is limited to just 50 pieces. Its most striking feature is the Ceratanium® case, which experts at IWC have been working on for more than five years. The special manufacturing process gives the metal a black, ceramic-like surface. Ceratanium® is both light and unbreakable like titanium, but also as hard and scratch-resistant as ceramic. The material also scores well for its high skin tolerance and corrosion­ resistance.

Aquatimer 50 years edition Ceratanium IWC Schaffhausen

The dial is black, and some components of the IWC­manufactured calibre 89802 have also been coloured black, such as the rotor of the self- winding system. The technical features include a digital perpetual calendar that displays the date and month in large numerals in the style of a digital watch, automatically recognising different month lengths and leap years. The chronograph with flyback function displays stop times, combined in a totalizer at 12 o’clock.

Like all Aquatimer models, this watch, which is water­resistant to 10 bar, features an external/internal rotating bezel for setting the dive time. The IWC SafeDive system ensures that the internal rotating bezel can only be adjusted when the external bezel is rotated in an anticlockwise direction. As a result, even if the external bezel is acciden- tally moved, zero hour – the time at which the diver can return to the surface without the need for decompression stops – cannot be exceeded. Thanks to the quick­change system, the black rubber strap can simply be replaced with another strap.

The special­edition Aquatimer with a Ceratanium® case is available in IWC boutiques from September 2017 at the price of CHF 50,000.

What exactly is Ceratanium®?

Lorenz Brunner heads up materials development at IWC Schaffhausen. Here, he tells us about the main advantages of a new case material, Ceratanium®, and provides an insight into the manu­ facturing process.

What is Ceratanium®?
Ceratanium® is a groundbreaking new material, based on a titanium alloy, that combines all the advantages of titanium and ceramic. It is as light and tough as titanium but as hard and scratch-resistant as ceramic. Other compelling features are its skin-friendliness, high resistance to corrosion and striking matte black colour.

What inspired the unusual combination of titanium and ceramic?
The main reason was the fact that both materials have such excellent properties. Titanium is about a third lighter than steel, extremely rugged and also bio-compatible. Ceramic is non-wearing, extremely hard and scratch-resistant. On top of that, both titanium and ceramic are inseparably linked with the history of IWC. In 1980, we launched the IWC Porsche Design titanium chronograph – the  first wristwatch with a case, crown and  push-buttons in titanium. The next new product followed soon after, in 1986, with the Da Vinci Perpetual Calendar (Ref. 3755), when IWC unveiled the first wristwatch with a case made of black zirconium ceramic. Later, we were the first watch manufacturer to make a case from black boron carbide ceramic (Ingenieur Automatic Edition “AMG GT”, Ref. IW324602) and brown silicon nitride (Pilot’s Watch Chronograph Edition “The Last Flight”, Ref. IW388004/ IW388005 / IW388006).

What was the main reason for the development of the new material?
Our brief at the start of the five-year development process was to create a black or very dark material suitable for making a completely black watch. The new material would not only have outstanding properties but also give us more freedom during manufacture than ceramic. In the past, we’ve made black cases with ceramic or rubber-coated stainless steel.

What particular challenges does ceramic pose?
Ceramic is a powdery raw material that is mixed to create a homogeneous mass, shaped and then sintered in an oven at extremely high temperatures. During the sintering process, the material shrinks by around a third. We need to factor the reduced dimensions into the design phase. The minuscule tolerances acceptable for mechanical watches make the job incredibly demanding. Apart from that, it isn’t possible to machine ceramic using conventional processes. For example, you can’t drill holes in it after sintering because it might split. For all these reasons, designing a ceramic watch is a different ball game from making a metal one.

And is that not the case with Ceratanium®?
Ceratanium® is based on a titanium alloy produced specially for IWC. We make all the case components from this metal, milling, turning, drilling and polishing them until they’ve reached their final shape. Only then do the parts go into the oven. The special composition of the titanium alloy initiates a diffusion process and the surface of the material is transformed into ceramic.

What does that mean exactly?
After sintering, the surface has the same properties as ceramic. It’s extremely hard and scratch-resistant and takes on its distinct colour. But the thing is: it isn’t a coating. During the sintering process, a “phase transformation” takes place. As a result of this change in the structure, the ceramic surface bonds directly with the material. It’s a bit like a loaf of bread: during baking, bread develops a crust that’s difficult to remove afterwards.

Couldn’t you make a black case using another method?
But IWC really unleashes its functions. The collection ranges from a simple hand-wound view to chronographs with and without having split seconds, world-time watches, and perpetual calendars. And with its restricted Significant Pilot’s Heritage Watch 55, IWC even restores its unique 55-mm diameter. It closely approximates the style on the authentic – with beige luminous material in addition to a matte case – though it has a modest seconds display (the authentic model had a central seconds hand).
Most iwc schaffhausen manufacturers use PVD coating for their black cases. In this process, metal is placed in a vacuum chamber and given an ultra-thin DLC (diamond-like carbon) coating. But this type of coating is a little like the shell of an egg: it can chip or break off if the watch is hit or bumped. That doesn’t meet our high quality standards. In the light of our extensive experience in case manufacture and hardening processes, IWC decided not to use this particular process.

How do you plan to use the new material now?
With the Aquatimer Perpetual Calendar Digital Date-Month Edition “50 Years Aquatimer”, we’ve shown that we can make all the case components – the clasp, rotating bezel and case back ring – from the new material. Now we need to wait and see how iwc mark xvii lovers react to it. But I assume we’ll be using Ceratanium® in the future for other models. It’s suitable for any application where we need lightness, ruggedness, corrosion-resistance, hardness and a striking black colour.