Computer Simulation of the Hot Pressing Process in Multi-phase Composite Ceramic Tool Material and the Technological Design II.Simulation of the Densification Kinetics and the Technologial Design

Models of the heat transmission in the hot pressing process of ceramic tool material have been built theoretically. Then, with the example of Al 2O 3/SiC/(W,Ti)C ceramic tool material, designs of the hot pressing technology are made through the study of the temperature field in ceramic blanks by means of the computer simulation. Results show that the temperature increasing and decreasing rates and the existing of the voids before sintering have a great effect on the temperature field in ceramic blanks. Under the experimental conditions, it is suitable for the rates of temperature increasing and decreasing to be 0.5～ 0.75℃/s and 0.33℃/s, respectively through the comprehensive consideration of the need of both the material property and the manufacturing efficiency. From the view of the temperature field, the ceramic blanks should be cold-pressed first before hot pressing. Thus, the initial relative density of the blanks can be increased and the temperature difference can be reduced. As a result, the physical and mechanical properties of the ceramic tool material will be improved.