تاثير الاختزال على زجاج الخزف المؤكسد العالي الحرارة (Stoneware) : دراسة تجريبية مقارنة == The Effect of Reduction On The Oxidized High Temperature Pottery Glaze (Stoneware) : Comparative Experimental Study
Author name:
زيد لقمان محمد علي الهلالي
Supervisor name:
احمد هاشم عبد الكريم الهنداوي
General topic:
Fine Arts
Specific topic:
Porcelain
Degree:
Master
University:
University of Baghdad - College Of Fine Arts - Fine Arts Department
Language:
Arabic
University location:
Baghdad
First pages:
18T1239 - p.pdf
Abstract:
تناول البحث تاثير الاختزال على الزجاج المؤكسد العالي الحرارة, اذ ان مشكلة البحث, معرفة التاثير على النتائج اللونية ونسيج السطح بالياته المختلفة بالمقارنة مع نتائجه بالحرق في الجو المؤكسد, وقد هدف البحث وضع قاعدة بيانات لتلك النتائج باختلاف الاجواء.تناول | This research dealt with the effect of reduction on the high temperature glaze, as the problem of the research is to know the effect on the color obtained and the effect on the surface texture in comparison with the results obtained in oxidized environment. The goal of the research was to establish a database for those results obtained in different environment.The second chapter dealt with the historical roots for the reduction technique used in the old civilization where different methods and techniques used.The research also studied the types of kilns and the methods used in both reduction and oxidization using fuel burn kilns. The research studied the most effective oxides used in reduction kiln especially Iron and Copper oxides in different ratios as well as different burning program.Three different glazing mixes was prepared, added to each one of them seven different quantities of the following : Three different glass mix been chosen after several experiments, then different percentage of oxide added was determined, red Iron oxide (Fe2O3) in percentages, 0.5, 1, 2, 4, 8, 16, and 32, Copper Carbonate (CuCO3) in percentages of 0.25, 0.5, 1, 2, 4, 8, and 16, the third mix was exactly the same second mix added to it 2 percent of Tin oxide (SnO2).A serious of firing program made in a Gas fired kiln with a firm downdraft controlled for both reduction and oxidation firing. Mean time all experiments done according to specific program through controlling the rate of temperature rise and timing the firing environment, the glass maturity temperature was set to be 1250 C°.Chemical and physical tests applied on the result of above which unveil a wide variation depending on the firing environments and the type of mix, all results shown in a comparison tables.Glaze mix was calculated according to glaze master program which shows the relation between the three oxide mix used (RO, R2O - R2O3 - RO2) accordingly the temperature and the property of glaze surface determined using Seger’s rule and Matrix dimensions system.Results were evaluated according to approved standards and scientific resources, as well as on the theoretical knowledge and previous studies.results were studied to find out the reason behind the color changes and the changes in surface texture in different firing environments.Most important conclusions are : • Reduction achieved good results for the high temperature glaze through increasing the activation of the material.• Celadon and Copper red colors obtained by adding low percent of coloring materials.• The desired copper red color was obtained by adding Stannic oxide (SnO2) which is quadratic ion (Sn+4 ) in oxidized environment to transform it to Stannous oxide (SnO) which is divalent ( Sn+2 ), in turn it will deoxidized during cool down process.• There was more shining and more even surfaces obtained in reduction process due to weakness in its structure for losing its binding Oxygen. The researcher recommended and suggested the following; • Studying the effect of reduction of high temperature glaze on porcelain clay.• Studying the variety results achieved by adding Copper and Iron oxides on high temperature glaze.• Studying the production of crystalline high temperature glaze in reduction environment.
