Messages: 36386 Location: NYC
Registered: May 2005
Information re: fabrication of Cermet
Sat, 16 February 2013 23:10
As you all know, the Deep Sea Chronograph was introduced a few weeks back at SIHH in a 44mm watch with Cermet case.
The fabrication of Cermet is a fascinating, and extensive process, as described below.
**The description below is more Rosetta Stone than lab coat. That is, translated...for unlike Robert Pollard (for you, Jit), "I am not a scientist"
Base Material
Fabrication of microspheres (powder) in ceramic:
The micro particles of aluminum oxide (Al2O3) begin as crystalline powder. This is mixed with a gas and an oxygen-enriched air which forms a mixture that is ignited in a type of torch. The combustion temperature surpasses the fusion point of aluminum crystals (more than 2500°C), and they become tiny spherical droplets. The spheres are then quickly cooled to room temperature, where they become solidified.
Mixing the ceramic microspheres with the aluminum powder:
The mixture is heated in a vacuum to prevent any oxidation.
The aluminum is then compressed with the microspheres of ceramic and the base material is achieved.
The case is then cut using the base material.
Protective layer of Ceramic
Anodisation by electrochemical process:
The piece is submerged in an electrolytic bath. The electrical current introduced transforms the aluminum into ceramic, which then adheres to the piece itself, allowing for an outer layer of exterior protection.
FROM Wikipedia re: the Process
The anodized aluminium layer is grown by passing a direct current through an electrolytic solution, with the aluminium object serving as the anode (the positive electrode). The current releases hydrogen at the cathode (the negative electrode) and oxygen at the surface of the aluminium anode, creating a build-up of aluminium oxide.
Advantages of Cermet
Cermet is approximately 33% lighter than titanium, allowing for a lightweight watch at 44mm.
Cermet is more shock resistant than pure ceramic.
The ceramic helps solidify the entire case, which becomes useful when worn during sporting activities
Cermet is resistant to very high temperatures, which is why it is used in Formula 1 engine valves
Resistance to scratches is better than both steel and titanium, thanks to a 40 micron layer of ceramic
Cermet allows for the marrying of the best qualities of both ceramic and aluminum, and is used in aeronautics, race car engines, as well as electrical components.
Information on the models...
Technical characteristics
Movement
• Mechanical automatic movement, Jaeger-LeCoultre Calibre 758, crafted, assembled and decorated by hand
• Frequency: 28,800 vibrations per hour
• 47 jewels
• 6.8 mm thick
• 340 parts
• 65-hour power reserve (36 hours with chronograph in operation)
Functions
• Hour
• Minute
• Small seconds
• Chronograph: hour and minute counters, central seconds hand
• Chronograph mode indication: ON, OFF, reset
Dial
• Matt black
•Luminescent hands and hour-markers (orange-coloured for the Jaeger-LeCoultre Deep Sea Vintage Chronograph Cermet)
Aiguilles
•Openworked baton-type, luminescent (orange-coloured for the Jaeger-LeCoultre Deep Sea Vintage Chronograph Cermet)
Case
• Reinforced cermet
• 44 mm diameter
• Sapphire crystal
• Water resistance: 10 bar
Strap
• Trieste calfskin leather, pin buckle, steel, black PVD
Reference:
• Q208A570, Jaeger-LeCoultre Deep Sea Chronograph Cermet
• Q208A57J, Jaeger-LeCoultre Deep Sea Vintage Chronograph Cermet
Thank you to JLC for providing this info!
Howard - Moderator...Audemars Piguet & Jaeger-LeCoultre
- boa2