FAQs on Black Diamond - Nitride Bonded Silicon Carbide
What is Black Diamond?
Onex’s Black Diamond high-performance product is a nitride-bonded silicon carbide (NBSiC).
The silicon carbide is super-heated in a domestic nitrogen atmosphere furnace, ensuring a US-based supply of NBSiC for applications, such as saggers, muffle sections, exhaust sacks, abrasion sleeves, and crucibles.Onex can assist with design support on custom-formed shape needs with the Black Diamond application, including large and complex shapes.
How are Black Diamond parts installed?
Considered at time of design, either chemical or mechanical attachment style. Chemical attachments include RTV (high temp), specialty cements,another mortar or cement of end user’s choice. Mechanical attachments include dovetail slots/inserts, weld-holes/caps. A combination would be a “backer” mortar behind liners with housing securing, or “key” tiles to lock liner position.
Can the liners hold pressure?
Black Diamond parts always have some porosity, we have methods of minimizing porosity. The housing outside of the Black Diamond liner should be depended upon to hold pressure.
Can the liners be installed on the outside of metal components?
The thermal expansion of metal > the thermal expansion of Black Diamond. A Black Diamond liner applied to the outside of a metal component would have potential to crack with ∆T. If this was required, Onex would opt for a segmented design to reduce stresses.
Do Black Diamond liners have impact resistance?
Generally, ceramics are not preferred for impact. However, Black Diamond NBSiC does withstand some impact. Impact scenarios should be indicated at time of quote.
For highly abrasive areas in a process NBSiC is extremely beneficial. Size of material should be in the 0.25” minus zone to have best results with NBSiC. If impact is not expected, but possible, we would recommend a PU or RTV backing to prevent liner segments from entering process flow in case of cracking.
How can I prevent thermal shock of my liners?
At time of design, minimizing changes in wall thickness / minimizing thickness in general, are preventative methods for thermal applications. Preheating components used in molten metal handling are always preferred. Baffling areas exposed to more direct heat than other areas of a liner is beneficial.
What are the typical failure modes of Black Diamond?
Flexural – Design for stress reduction
Oxidation – Custom blends can be used to mitigate
Long-term Wear – We design and select grade to maximize wear-life
Thermal Shock – Preheating, maintaining wall thickness, equalize heat distribution
Contact Onex to discuss your NBSiC needs today.
