doi: 10.3850/978-981-11-0749-8_669
Plasma Nitriding of Inner Surfaces in the Mini- and Micro-Nozzles for Joining
T. Aizawa1 and K. Wasa2
1Department of Engineering and Design, Shibaura Institute of Technology
2TecDia, Co. Ltd
Abstract
Miniature products have been high-lighted in every engineering field since the first application of silicon technology to micro-fabrication of electric circuits, sensors and transducers. In the final stage of this microfabrication, these functional units and structural parts must be micro-joined together and micro-integrated into the final product. A nozzle was a key mechanical part to make accurate and fine deposition of joining adhesives onto their surfaces and interfaces. In accordance with further miniaturization in the joined parts, finer nozzles with the inner diameter of 10 µm were demanded in market. The low temperature plasma nitriding process was developed as a surface treatment to improve the engineering durability of mini- and micro-nozzles. AISI316 nozzle specimens were utilized to demonstrate that their inner surfaces had higher hardness than 800 HV after plasma nitriding for 14.4 ks at 693 K. These hardened AISI316 nozzles were expected to be working instead of the ceramic-head nozzles in severe joining operations.
Keywords: Micro-fabrication, Mini- and micro-nozzles, Stainless steels, Plasma nitriding, Inner surfaces, Hollow cathode device, Nitrogen interstitials, Hardness.
