Industrial Scale Field Assisted Sintering: Is an Emerging Disruptive Manufacturing Technology

摘要

There has been significant progress in the synthesis and processing of nanoparticles by various routes including solid (e.g., mechanical grinding), vapor (CVD, thermal, and electron-beam evaporation), and liquid (precipitation and pyrolysis) technologies. The next step is to use these nanoparticles to make net-shape components using a process that will retain the nanostructured properties in the parts. Nanostructured materials in the form of coatings show increased surface resistance properties including wear, corrosion, erosion, and thermal resistance. There are significant challenges in making net-shape components having nanograined microstructures. Typical steps involved in making net-shaped components using powder are green compaction, sintering at elevated temperatures, and hot isostatic pressing to improve density. During these conventional sintering and hot pressing processes, there is significant grain growth due to long thermal exposure, thereby destroying the effective functionality of nanograined materials in the final component. To maintain nanograined microstructures in the compacted and sintered product, sintering time and temperature must be reduced significantly.