Question

In flat plate test, concave glazed side refers to _________ in glaze which will lead to _________.

• A. Tension, peel
• B. Tension, craze
• C. Compression, peel
• D. Compression, craze

Hint:

In ceramics, tensile stress causes crazing (fine cracks), while compressive stress leads to peeling (glaze detachment).

Answer 1

The Correct Option is B

The flat plate test is used to analyze the stress distribution in ceramic glazes. The concave or convex nature of the glaze determines whether it experiences tensile or compressive stresses.
Step 1: Understanding the Stress in Glaze Layers - If the glazed side is concave, the glaze layer is under tension. - If the glazed side is convex, the glaze layer is under compression.


Step 2: Defining the Failure Mechanism - Tensile stress in the glaze leads to crazing, which appears as fine cracks on the surface. - Compressive stress in the glaze leads to peeling (or shivering), where the glaze detaches from the ceramic body.


Step 3: Evaluating the Options - Option (A) - Incorrect: Tension causes crazing, not peeling. - Option (B) - Correct: Tension leads to crazing, which occurs when the glaze contracts more than the ceramic body. - Option (C) - Incorrect: Compression causes peeling, not crazing. - Option (D) - Incorrect: Compression does not cause crazing.


Step 4: Conclusion Since concave glazed surfaces experience tension, leading to crazing, the correct answer is option (B).