Final answer:
The hardening or glazing of ceramic ware in a kiln involves applying a mixture such as a slip to the surface of pottery and firing it at high temperatures, commonly around 900 degrees Celsius. This process can also include a second firing with metallic glazes to create lusterware. Advanced processes like sintering and sol-gel contribute to the manufacture of high-strength ceramics.
Step-by-step explanation:
The process of hardening or glazing ceramic ware by heating it in a kiln to a specified temperature is a critical step in ceramic production. This process involves coating the pottery with a liquid mixture, often containing silica, which forms a glassy surface upon being subject to high temperatures. For instance, slipware pottery uses a slip made of fine clay particles mixed with water, which is painted onto the pottery. It requires skill to apply because it matches the color of the dry clay and only reveals its true tones after firing.
During the firing process, which may reach temperatures around 900 degrees Celsius, as mentioned by Steven, the look of the ceramic ware is finalized. This heating not only hardens the ware but can also impart luster or gloss if materials such as metallic glazes are applied for a second firing at lower temperatures, producing an iridescent shine known as lusterware.
Additionally, processes like sintering and sol-gel can produce fine powders of ceramic oxides, which are used to manufacture pottery with uniformly sized particles, resulting in high-strength ceramics. Similarly, quartz, an integral component in ceramics, can melt at 1600 °C to form a glass or amorphous silica, which has a low coefficient of expansion, allowing it to withstand rapid temperature changes without fracturing.