Impact resistance of boron nitride & other ceramics?

[blueandwhiteg3]

I'm looking for some information on the impact resistance of boron nitride and other ceramics.

I've been looking for data like this online and the data has been at best incomplete. Or comparing different impact values.

Can anybody point me to some good data? Or provide a rough outline of how boron nitride compares to other ceramics?

 

[unclesyd]

Here is data from NIST for most forms of Silicon Nitride. You will have to take this data and compare it with specific materials for your requirements as there are to many to compare with. If you are trying to choose a ceramic there are a lot of other physical parameters that need to be considered.
If you just want a comparison for a broad range of ceramics you will probably have to get a materials book.

You might look around NIST for data on additional materials

http://www.ceramics.nist.gov/srd/summary/ftgsin.htm

 

[tomwalz]

Generally Transverse Rupture Strength is given and you guess from there, at least in my experience.

Impact resistance is hugely dependent on how the materials are used.

tom

Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

 

[EdStainless]

I agree with Tom.
TRS is a real property, impact toughness has to do with application.
Interesting, I used to look at thermal shock data. this has a lot to do with toughness, but not as dependent on how the part is tested.
all of the ceramics are quire brittle compared to metals. This makes test methods very delicate.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[blueandwhiteg3]

I agree that this kind of thing is highly dependent upon the application and test being performed.

I was not aware of the NIST data. It is part of what I was looking for, but it's not complete, or terribly well structured for my goals.

It would be particularly nice if there was a somewhat subjective summary-comparison of impact resistance somewhere.

 

[tomwalz]

If it was my problem I think I would buy machining inserts or similar small pieces of material and impact test them.

However, the material designation alone, is not nearly enough information. We spend years developing cermet tipped saw blades for mills, plats, etc. One grade of material can be greatly different than another. I had a $15,000 test ruined because the manufacturer had switched his processing methods.

I would try CoorsTek or see if I could find a university paper. The University of Washington in Seattle does a lot of ceramics research and I have always found their library to be very helpful.

If this is for an industrial application you need to have someone on the materials side who will produce consistent material.

Tom


Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

 

[armanand]

There are at least 2 types of Boron Nitride - the hexagonal BN (soft, similar to graphite in crystal structure, this is an easily machinable ceramic) and the cubic (very hard, similar to diamond in crystal structure, used typically in cutting tools).

On the soft type, there are many grades of hBN available commercially. Since thermal shock is a function of its strength, co-efficient of thermal expansion and thermal conductivity as well - you will have to be careful to use this as a guide for impact strength.

Some properties are listed in this website on hBN. You can call them if they have more info that is not published in their website:

http://www.momentiveceramics.com/downloads/documents/81507.pdf

Their phone number is: (440) 878 5728.

Hope this helps.

 

[ultramat]

You can find ceramic properties for Alumina and Zirconia in the following link:

http://ultra-mat.com/site/products/advanced-ceramics

I hope this is helpful.