Sorry it took so long for me to get back to you. Here is a couple of things that you requested. The pH of our bath runs 13 - 13.3 caustic at 2400 F. Your CeTZP ceramic sleeve bearings were in our bath for about 3 to 4 months. If not for the drag factor we would be running your CeTZP sleeve bearings. I found there was no indication of wear at all. If at anytime we have a use for a sleeve bearing that will last I will be in touch with you. Thanks again, you have a very good product.
We used the tiles together with alumina ones during a milling of a lot of abrasive materials such as Alumina, Silica, Salt, Magnesium Oxide, etc. during 100 hours of continuous milling process when high speed flow of room temperature pressed air with particles of milled material collide with lined wall. After all milling trials on your CeTZP ceramic tiles we had not found any wear.
Please do not hesitate to ask any additional questions – I shall be glad to help you.
Following are answers to your questions:
Alumina was slightly worn.
We did not find cracks in your CeTZP tiles, whereas number of Alumina tiles broke down.
There was not any discoloration on both tiles.
The performance of the CeTZP is better than Alumina.
Leonid Zisman, Super Fine Ltd.
From: Frederic P......, France
Subject: Re: CeTZP samples
Date: Fri, 16 Dec 2005 18:46:53 +0100
......... For a current development we need a strong ceramic not sensitive to hydrothermal degradation, able to withstand few years into harsh downhole environment. Yttria stabilized Zirconia fails in such environment and MgO-ZrO2 has low mechanical properties. CeTZP seems to fulfill all our requirements.
In order to validate CeTZP in our environment, I would be very interested in having a sample to test. Failure mechanism of Y-PSZ is surface degradation up to total degradation. I do not need particular shape, just a sample representative of your process. Obviously, we are ready to pay for it.
I'll be glad to discuss more deeply of my application, Thanks for your cooperation, Regards,
Date: Tue, 20 Dec 2005 10:56:43 +0100
Thanks for your message.
Encountered pH are between 1.5 to 7 with salinities between 0 and saturation. Many other species are present, especially CO2 and H2S. For this current application, temperature will be 300 F.
We will be glad to share the results with you. Shiping address is......
Thanks for your message. Parts are still under test, hot water at 150C, and they are in really good shape with no evidences of degradation. Tests are going on under other corrosive environments. I begin to recommend your product to my colleagues for particular applications...... The scope is to show the differences with the most corrosion resistant Zirconia, MgO-ZrO2.
Thanks again for your cooperation, Best regards, Frederic
I had a look at the samples you sent. Please find some comment on microstructure and hardness and toughness results. Sample 1: orange 28 mm diameter disc HV10 = 966 kg/mm2 Indentation fracture : 15.44 MPa (m)(1/2) Fine uniform structure with only few small pores visible at 100 or 200 x with diameter below 2 microns - secondary darker ceramic phase distributed in the material
Sample 2: yellow small fractured part HV10 = 1025 kg/mm2 Indentation fracture : 15.38 MPa (m)(1/2) Fine uniform structure with only few small pores visible at 100 or 200 x with diameter below 2 microns - secondary darker ceramic phase distributed in the material
Sample 3: orange 28 mm diameter disc HV10 = 966 kg/mm2 Indentation fracture : 15.44 MPa (m)(1/2) Fine uniform structure with only few small pores visible at 100 or 200 x with diameter below 2 microns - secondary darker ceramic phase distributed in the material ....... Kind regards
To date we have run several tests with the CeTZP platen you sent us. So far everything is running very well. We have done several runs at 1100C (in vacuum of 10-6 torr) and the platen saw loads up to 1500MPa with no signs of failure or indentation in the surface from our test specimen.