Machining and characterization of advanced ceramic materials pre-sintered at different temperatures

ABSTRACT

The machining of pre-sintered advanced ceramics is a technique used to enhance the strength of the compact, facilitating machinability compared to green ceramics (brittle) and fully sintered ceramics (extremely hard). Several factors influence this process, including pre-sintering temperature, machining parameters, compaction method, and ceramic material type. This study aims to evaluate the influence of different pre-sintering temperatures on the turning process of advanced ceramics, seeking to identify the optimal condition for optimizing the manufacturing of ceramic components. A machining setup equipped with a feed force monitoring system using a load cell was employed. The analyzed properties included density, linear shrinkage, feed force, hardness, and surface finish (both pre-sintered and sintered) at four pre-sintering temperatures: 950°C, 1000°C, 1050°C, and 1100°C. The results indicated that increasing the pre-sintering temperature led to higher hardness and greater feed force. Regarding surface finish, higher roughness was observed at temperatures above 1000°C. The analysis suggests that a pre-sintering temperature of 950°C is the most suitable for alumina ceramics, as machining at this temperature resulted in the lowest hardness and feed force, reducing cutting tool wear and, consequently, manufacturing costs. Furthermore, no significant difference in grain size was observed among the samples pre-sintered at different temperatures.

Keywords:
Advanced Ceramics; Pre-Sintering; Surface Finish; Machining Forces; Parameter Optimization