Right material for ceramic nozzle

[fahmi.afk]

hi,

i'm doing a project on development of ceramic nozzle. can somebody help me by giving some information regarding the most suitable type of ceramics that have the good wear resistance and high melting point.

thanks.

 

[Space_Cowboy]

It would help to describe the application and conditions you intend to use this nozzle for.

 

[fahmi.afk]

thanks for the tips.

the nozzle intend to be used as part of a rocket. it will be tested using a 100N rocket motor. so, the nozzle will be under a high pressure, temperature and velocity conditions due to the fast flow of the rocket's gas. therefore, the ceramic material needs to be able to withstand the high pressure and temperature up to 2700 degree celsius.

i've done research on alumina(aluminum oxide), but I'm stuck with how to make it become stronger. is it possible for the alumina to be coat with another ceramic material such as fireclay?

hope somebody can give me more information regarding this matter.

 

[Space_Cowboy]

I used to be involved in 'high power' model rocketry until a few years back when the hobby was blackballed by the ATF, the agency that tested and issued permits for handling the higher power stuff. This was due to concerns that some terrorist would use the hobby motors for nefarious purposes.

Anyhow... Most of the 'reloadable' solid fuel motors I had been familiar with at the time, used machined carbon for the nozzles due to its relatively low cost, high heat resistance and ease of machining. The single-use motors used some kind of impregnated black phenolic composite for their nozzles. The smallest motors (Estes) used fireclay, and to my knowledge, pyrotechnics people still use this type of nozzle on the rocket motors that lift their fireworks displays.

In my experience I don't remember anyone using ceramics. While the heat resistance of some ceramics may be attractive, most ceramics I'm aware of have poor resistance to mechanical loads. They tend to shatter which could be very dangerous.

Are you designing this motor for multiple uses? Is it solid-fueled, hybrid, or liquid?

 

[fahmi.afk]

hi space..

the motor is for single-use and it is a solid propellant motor.

i already re-planned my project. the nozzle will be made up from alumina(ceramic), methylated spirit(solvent) and polyvinyl butyral(binder). in addition, i planned to coat the inside surface of the nozzle. however, I'm still stuck at finding the right coating material.

so far, your suggestion is a new thing to me since i never heard of it or make a research on that material. can you give me more informaton regarding the impregnated black phenolic composite?

thanks for the help.

 

[Space_Cowboy]

http://www.aerotech-rocketry.com/

This company's single-use solid fuel rocket motors use the material I mentioned. I think it's carbon impregnated phenolic but I don't know for sure. The sizes up to 'G' class are available without a BATF-issued low-explosive user permit. The 'G' class is in the range of 80-160 N/sec.

http://en.wikipedia.org/wiki/Model_rocket_motor_classification#Motor_impulse_by_Class

 

[fahmi.afk]

thanks for the info.

i have another thing to ask you. what is the best high temperature sealant? the reason why i asked this is because the nozzle will be formed into two separate part which will be combined using a sealant. so, i need to find the sealant.

hope you can help me on this. thanks.