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.
Wednesday, February 25, 2009
Tuesday, February 24, 2009
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.
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.
Monday, February 16, 2009
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. :)
It was a nice one even little bit boring. :)
Wednesday, February 11, 2009
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.
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.
Tuesday, February 10, 2009
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.
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.
Monday, February 9, 2009
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.
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.
Friday, February 6, 2009
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.
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.
Thursday, February 5, 2009
Kneading with the Big Kneader
A meeting was held to discuss about the further tasks that has to carried out regarding the projects.
The first thing is that the kneader has to be checked for the vacuum problem and identify the possibilities. Then also for the Arg. project, the test samples have to be sieved and separate the fibers to be checked under the microscope for the lengths.
Furthermore, the geometrical parameters of the 3rd bath of MH project has to be checked like density and shrinkage. And also the extrusion of modified 92g EKA-S 4mm fibers.
The kneader was checked and I could observe that the beading between the two lids of the main feeding has some openings which takes air inside in the vacuum condition. Kneading of the test sample of earlier kneadings were sieved to separate fibers.
The sample from the Brgts project, the earlier sample shows a weight loss. After the system became equilibrium, another sample was put in to water. The sample was kept five hours in hot water, taken out, dried using a tissue and kept for further drying in air.
The first thing is that the kneader has to be checked for the vacuum problem and identify the possibilities. Then also for the Arg. project, the test samples have to be sieved and separate the fibers to be checked under the microscope for the lengths.
Furthermore, the geometrical parameters of the 3rd bath of MH project has to be checked like density and shrinkage. And also the extrusion of modified 92g EKA-S 4mm fibers.
The kneader was checked and I could observe that the beading between the two lids of the main feeding has some openings which takes air inside in the vacuum condition. Kneading of the test sample of earlier kneadings were sieved to separate fibers.
The sample from the Brgts project, the earlier sample shows a weight loss. After the system became equilibrium, another sample was put in to water. The sample was kept five hours in hot water, taken out, dried using a tissue and kept for further drying in air.
Wednesday, February 4, 2009
Kneading with the Big Kneader
Since the cleaning of the big kneader takes about at least two hours the kneading was started early in the morning. Now it is with the same Arg. body and 8mm fibers and same as earlier the test samples had to be taken out at intervals. After 4 hours and 45 minutes, we tried to vacuum the device to make an extrusion of the kneaded material but the vacuuming seemed to be not working. Hence, the extrusion was stopped and cleaning started, it took about 3 hours to be finished.
For another project I had to give hand by doing a test on three samples. Each and every sample had to be placed in hot water of which the temperature had to be between 500 - 600 degrees. The beaker with water was placed on the electronic heater (electronic hotplate) and when the temperature was in equilibrium in between the mentioned temperature a sample (Tablet like) was carefully put into the middle using a tweezers. After five hours the samples had to be taken out and dried and weigh. The intention was to remove the binder which is dissoluble in water.
The weight of the first sample has reduced but it was kept to be dried more in air.
For another project I had to give hand by doing a test on three samples. Each and every sample had to be placed in hot water of which the temperature had to be between 500 - 600 degrees. The beaker with water was placed on the electronic heater (electronic hotplate) and when the temperature was in equilibrium in between the mentioned temperature a sample (Tablet like) was carefully put into the middle using a tweezers. After five hours the samples had to be taken out and dried and weigh. The intention was to remove the binder which is dissoluble in water.
The weight of the first sample has reduced but it was kept to be dried more in air.
Tuesday, February 3, 2009
Kneading with Glass Fibers (small kneader)
Kneading of the Arg. body was started in the morning with glass fibers using the small kneader and it had to be kneaded for five hours and test samples had to be taken out after 30min and each and every hour. These samples will be sieved and fibers will be separated to observe the length of the kneaded glass fibers. Cleaning of this small kneader takes about 45 min to one hour.
The kneading has to be done using the big kneader so that it was cleaned off the oil and fixed for the next day use.
Al2O3 fibers still break up in the sintering process even this time another program was used. Now I am going to check whether the heating rate at the beginning has something to do with the fiber explosion.
The kneading has to be done using the big kneader so that it was cleaned off the oil and fixed for the next day use.
Al2O3 fibers still break up in the sintering process even this time another program was used. Now I am going to check whether the heating rate at the beginning has something to do with the fiber explosion.
Monday, February 2, 2009
Failure in the Sintering Process
As a sample of test sample 2 was put to the furnace CeramAix to sinter I looked at the results today in the morning. But there was no sample left on the Zirconia substrate. Probably the fiber is broken into pieces and blown away with the heat flow.
Since it is arguable about the inside flows which can break the structure of the fibers, the use of a crucible would be a good idea and I was provided with a crucible. Using it another sample was put to the furnace and this time it will go upto 14000C and sinter Al2O3.
Since it is arguable about the inside flows which can break the structure of the fibers, the use of a crucible would be a good idea and I was provided with a crucible. Using it another sample was put to the furnace and this time it will go upto 14000C and sinter Al2O3.
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