The Use of Capability Indices in Process Evaluation of Ceramic Materials

In order to manufacture products of acceptable quality within predetermined specification limits, an evaluation of the manufacturing process through the use of capability indices is necessary. Capability indices are used in order to evaluate a process and to monitor the product characteristics and the results of quality improvement cycles. The three point bending strength of kaolin ceramic specimens produced by two different production processes (slip casting and hydroplastic extrusion) were investigated. It was found that under statistical control and normal distribution of strength values, the process capability indices Cp, Cpk, regardless of any disadvantages and the fact that they have limitations, can be combined with other techniques in the field of statistical process control and become valuable tools in process evaluation of ceramic products.