Low Temperature Copper Red Glazes Produced Through Reduction In Oxygen and Inert Atmosphere
The red copper glazes which possess a high aesthetic value are one of the important construction stones of the art of ceramics.These reduction artistic glazes’s have an history going back to 2000 B.C. , stretching out to Middle East and Egypt, but they gained their real development and importance in China, starting from the years 600 A.D. The red copper glaze which had attained its most brillant period during the Ming reign, has disappeared through time as the result of various reasons. In consequence of the efforts to re-create this color, different colors having an aesthetic appearance were produced, but the Chinese red of the Ming period, in all its sense, could not be attained.
The particles of copper which are in a good colloidal state in the matrix of the glaze, achieved the formation of the red copper glaze. As a reductible kind of glaze, obtaining a nice red, can only be realized with a lot of complex processes together. Among these, oksidation, redüction and nötr atmosphere with the conditions of firing form the most important stage. Usually in high degree temperatures, the color red is obtained with the reduction of the copper oxyde.
In forming of copper red glazes, copper compounds has an important role on the occurrence of red color occurrence of the best red tones is performed buy the controlled firing of variability of the oxidation, reduction and neuter condition of the kiln. During the firing, copper oxide forms the red color by being exposed to value change because of reduction. Generally copper red glazes have successful results at the high temperatures.
This study has four parts. The description and historical development of copper red glazes are found in the first part. Contemporary artists working on copper red glazes and sample works of them are stated in the second part. Raw material and coloring oxides used in producing copper red glazes and the firing technique are explained in the third part. In the fourth part; results are evaluated by forming different glazes recipes for copper red glazes that could be developed at 1200ºC applications and doing applications on sanitary bodies. Based on the evaluations how the best reduction is formed is also stated in this part.
The difficulties of obtaining a nice red, the content of the glaze compounds which will be reducted, the existence of special kiln conditions, the necessity to make high degree temperatures firings , are the reasons for which few ceramists have been interested in red copper glazes. In spite of all that, the red copper glaze because of its thousands years past and because of its artistic glaze speciality of an aesthetic value, will continue in the future to gather the interests of the potters and to be one of the important research domains of the ceramists.
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