Compression Test Samples

Smoothening of the compression test samples of MH was done. These are cubes of 10x10x10 mm³ and the dimensions and weights are taken for the calculation of the density. To ensure the effect of the direction of extrusion the samples are divided to giving 8 pieces for each and marking the direction of extrusion and the perpendicular direction of extrusion.

Studied about the EBS9M software which is used to log data from the Loomis extruder.

Vacuum Problem of AMK (Kneader)

We had a problem with the kneader with vacuum. It seemed to have lot of spaces in between its lids. The beading or the sealer which was there to prevent this had so many distortions so that air go inside very easily. And also in between the connecting parts of the machine (like walls in a square house) had a little space on the top where the vertical sealer ends.

So, thought of reducing the space and got the flash that I can use grease to fill out. But it took a lot of amount of grease but ultimately I could go down to -0.2 bars of the pressure, still with some minor leakages. Started the machine to see whether there are other leakages with the screw when its working. But it didn't give any effect and still had a decreasing pressure like -0.24 bars.

Prepared some samples for the compression test of MH project but the elevator was not working so that the Hoover/vacuum pump which sucks powders of cutting (otherwise it will spread all over the lab and it is not safe for everyones health) was not able to get upstairs from down. So I had to stop with only 16 specimens. Have to prepare more 14 specimens for the test and it's a little bit tough work with the small dimensions 10x10x10 mm³ since the accuracy has to be with a tolerance of 0.5 mm.

Presentation

Today as usual had a short meeting with the co-supervisor to discuss about the week's work. So many things has to do but today all the machines were occupied. In the evening a presentation from a Professor came from Poland held about the Chemistry of ceramic processing.
It was a nice one even little bit boring. :)

Sample Preparation for the Compression Test 2

For the MH project the compression test for EKS 92g and 127g pieces were cut yesterday and now it has to be smoothed for a proper grip. Using the sand papers the surfaces were flattened and smoothed at 20mm. 15 samples were prepared for the test and then dimensions were taken, the length and the diameter and also the weight was taken.

Al₂O₃ projects modified firing curve was tested and now the system goes upto 500⁰C and it seems to be broken now. But no carbon is there anymore.

Sample Preparation for Compression Test

For the MH project EKS-92g and 127g batches were sintered earlier and they had to be prepared for the compression test. Since the clay content is somewhat higher the almost all the samples seem to be cracked. So I selected the samples carefully for preparation and cut them into 22.5 mm pieces which have to be reduced and smoothed to 20 mm according to the German standard.

Another kneading of Arg. body was done without fibers for five hours. The cleaning took about 3 hours as before and it is really a long and unhappy process since the two screws of the kneader can not be taken out of the machine. Reaching corners which have to be really cleaned was a painful process.

Interesting Result of Al2O3 project

Kneading of a clear body of Arg. was started in the morning without fibers.

Al₂O₃ fiber is not broken this time. So discussed with the supervisor and checked the fiber under the microscope. It could be seen that still the core has not removed completely but the burnt carbon is remaining. It is quite difficult to make sure whether carbon is there only as a layer or a solid part. Hence, the fiber will be examined under the light microscope and photographed.

Kneading was done for five hours and then the cleaning of the machine. It was very hard to clean the machine as usually happened last times. There was an idea to use MH material to do an over extrusion so that the whole part of Arg. body will come out. But this time only an abrasive liquid was used and it took about 3.30 hours to finish the cleaning.

Another sample was put to the furnace and this time the final temperature will be little bit higher maintaining the previous ramps.

Sieving Fibers

For Bgts samples the system was prepared and another sample was put in the water after equilibrium.

Sieving of the fibers of kneaded test samples were done and two batches were sieved. The separated fibers were dried and then put into small holders named.