Diverse Development of Core Sintering Processes
The core of AlN ceramic fabrication lies in sintering. Currently, mainstream sintering technologies offer distinct characteristics to meet different performance and cost requirements:
Pressureless Sintering (PS): As the most common traditional process, it is conducted under ambient pressure and high temperatures between 1600°C and 2000°C. The process is simple, but pure AlN is difficult to densify, requiring reliance on sintering aids.
Hot Pressing Sintering (HPS): By simultaneously applying high temperature and axial pressure, this method significantly lowers the sintering temperature, shortens the process time, and yields ceramic bodies with fine grains and extremely high density, drawing considerable research attention.
Spark Plasma Sintering (SPS): This technique combines plasma activation with hot pressing, utilizing pulsed current to generate instantaneous high temperatures through discharge between particles, enabling extremely rapid sintering while effectively activating particle surfaces.
Microwave Sintering: This method uses the material's own absorption of microwave energy for rapid volumetric heating, offering advantages such as fast heating rates, short sintering times, and uniform grains. Studies show that using specific aid systems, AlN ceramics with high thermal conductivity can be obtained at relatively low temperatures, such as 1250°C.
Optimization Processes and Future Trends
To optimize the performance of AlN ceramics, precise process control is essential. The selection and ratio of sintering aids are key to promoting densification, improving microstructure, and controlling grain boundary phases. Sintering temperature and duration require careful balancing, as excessively high temperatures may lead to excessive liquid phase and product deformation. Additionally, controlling the appropriate sintering atmosphere is crucial for inhibiting material decomposition and promoting beneficial phase transformations.
Looking ahead, sintering technology for nitride ceramics is advancing towards the development of new, highly efficient sintering aids and the exploration of lower-temperature sintering processes. This will not only further optimize material structure and reduce production costs but also better align with the development trends of high-power and miniaturization in electronic devices, reducing energy consumption and thermal stress damage.
Industry Summit Propels Industrial Upgrade
Notably, as the world's largest and most comprehensive industry flagship event in the field of advanced ceramics, the "18th China International Advanced Ceramics Exhibition" will be held grandly at the National Exhibition and Convention Center (Shanghai) from March 24 to 26, 2026.
The exhibition is expected to span 55,000 square meters, bringing together over 1,000 renowned enterprises globally and attracting more than 80,000 professional visitors. It will cover core purchasers from numerous application fields including automotive industry, rail transportation, biomedical, aerospace, electronic communications, energy, and environmental protection. Representatives from leading industry enterprises will also be present to discuss cutting-edge technologies and market trends. The event is poised to become a significant engine driving the global advanced ceramics industry towards higher-end, intelligent, and international development, opening a strategic window to a trillion-yuan market.
