Significant progress has been made in recent years in developing silicon nitride ceramics. The advances that have been achieved are mainly based on an increasing understanding of processing and microstructure-properties relationships. New analytical methods and high resolution transmission electron microscopy (HRTEM) coupled with extensive phase equilibria studies have provided new insights into the grain boundary region and offer the possibility to tailor the microstructure for specific applications. Because of the anticipated break-through in industrial applications there are still considerablt; research activities at industrial laboratories as well as other research centres. This volume presents the contributions to the international workshop Tailoring ofHigh- Temperature Properties of Si3N4-Ceramics with 60 participants from 12 countries held on 6th - 9th October 1993 at SchloB Ringberg in Germany, the conference site of the Max- Planck-Society. Additionally, it contains all invited papers of the International Conference Silicon Nitride 93 held before the workshop on 4th - 6th October 1993 in Stuttgart/Germany. The book covers all recent research activities on silicon nitride ceramics and gives an overview with respect to recent developments.