Frequently Asked Questions
What is a pre-ceramic polymer?
A pre-ceramic polymer is a polymer that can be heated to elevated temperature or “pyrolyzed” to form a ceramic material.
What ceramics do Starfire Systems’ polymers form?
Starfire® Systems manufactures two classes of polymers which form different ceramics on pyrolysis in an inert environment. These polymers are polycarbosilanes, with a carbon-silicon backbone, that produce silicon carbide on pyrolysis and polysiloxanes, with a silicon-oxygen backbone, that produce silicon oxycarbides on pyrolysis. The polycarbosilanes include SMP-10 and a hot-melt polymer called SMP-730. The polysiloxanes are available in a range of compositions and are called “Polyramic® resins” as a group.
What is polymer infiltration and pyrolysis (PIP)?
Polymer infiltration and pyrolysis (PIP) is a method of fabrication of ceramic or ceramic composite parts from pre-ceramic polymers. During PIP a porous green body is immersed in polymer, often under vacuum. The polymer infiltrates the porosity in the part. The part is then pyrolyzed in an inert environment at elevated temperatures and the polymer decomposes into a ceramic. Owing to shrinkage of the polymer during the decomposition to a ceramic, multiple PIP cycles are required to produce parts of adequate density.
Do Starfire Systems’ products require hazardous and/or flammable handling for shipment?
Most, but not all, Starfire Systems’ products can ship by Federal Express without special handling that would be required for hazardous or flammable materials. Please consult your salesperson to learn which products are considered hazardous/flammable and should be handled appropriately. SDS are available for all Starfire Systems’ products.
What is the density of SMP-10? What is the density of SiC derived through pyrolysis of SMP-10?
At room temperature, the density of SMP-10 is about 1 g/cc. The density of SMP-10 changes as it is processed to higher temperatures. When pyrolyzed to temperatures such as 850C, the product is an amorphous SiC with a density of about 2.5 g/cc. When it is processed to temperatures near 1600C, the density increases to about 3.1 g/cc.
What temperature is required to produce a ceramic from SMP-10?
To convert from SMP-10 polymer into the ceramic Silicon Carbide, Starfire Systems suggests 850C minimum in an atmospheric pressure, inert environment. With increased temperature, the material becomes more dense. At temperatures up to 1200C, the material exhibits nano-crystalline or amorphous behavior and does not show up as a sharp peak with x-ray diffraction analysis. Between 1400C – 1600C, the ceramic material converts to a beta-SiC, and with temperatures 1800C – 2000C the ceramic material converts to an alpha-SiC.
If I cure the resin at 200C, is it a ceramic?
Because the polycarbosilane and polysiloxane resins are ‘pre-ceramic’ polymers, in the cured state they are not considered ceramic. Only when processing these resins to temperatures above 800C do they exhibit ceramic properties. In many cases, these resins are used with a fiber reinforcement, and therefore the fiber must also be rated for 800C or higher.
What solvents are in the resins when I receive them from Starfire Systems?
There are no solvents in the resins as delivered, and the resins are considered 100% solids. However, there may be trace solvents which remain from the manufacturing process.
Can I paint the polymer onto my metal surface and get a ceramic coating?
In most cases, no. The resin can be applied to a surface, and cured, but in order to pyrolyze to form a ceramic, the coating AND the substrate must be heated to temperatures up to or near 800C. Exceptions to this could be surface heating like plasma spray coating or microwave heating which do not heat the substrate substantially. Because most metals have thermal expansion values much higher than the ceramic material, these applied coatings will likely spall from the surface during cooling and will likely exhibit poor adherence.
Do I need to refrigerate products manufactured by Starfire Systems?
Yes, in almost all cases the resins, slurries, and prepregs made by Starfire Systems require cold storage to maintain shelf life. Cold storage should be -10C or colder to ensure maximum shelf life. Periodic venting of the containers may be required so refer to the appropriate process and handling document to learn more. Consult your salesperson to know if your product does not require cold storage.
At initial shipment from Starfire Systems, is dry ice needed in the shipping container?
Dry ice is not required for the initial shipment from the factory as any non-cold storage conditions are accounted for in the shelf life warranty. Upon receipt, product should be refrigerated immediately. Shipping in cold storage is available upon request.
What is the shelf life of products manufactured by Starfire Systems?
Typical shelf life for polymers is 12 months from ship date, and 6 months for slurries, molding compounds, and prepregs.
Does Starfire Systems accept credit cards?
Yes, credit cards are accepted and are processed through our customer service department.