Fining Technology of Al-50% Si Powder - A Material for Hermetically-Sealed Casing of Multichip SubsystemSheng-lin Yu1,2*, Song-bai Xue1 and Bang-yue Yin3
- *Corresponding Author:
- Sheng-lin Yu
Nanjing University of Aeronautics and Astronautics
210016 Nanjing, China
E-mail: [email protected]
Received Date: June 26, 2013; Accepted Date: August 20, 2013; Published Date: August 25, 2013
Citation: Yu S, Xue S, Yin B (2013) Fining Technology of Al-50% Si Powder – A Material for Hermetically-Sealed Casing of Multichip Subsystem. J Material Sci Eng 2:123. doi: 10.4172/2169-0022.1000123
Copyright: © 2013 Yu S, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
A material for hermetically-sealed casing of multichip subsystem needs the characteristics such as high thermal conductivity, low density, low thermal expansion coefficient, automatic sealing, simplicity and convenience of subsequent application workmanship .The material that is mostly suitable to be used is Al-50% Si compound material prepared by the spray deposition method. The powder metallurgy process (PM) was studied for preparing the Al-Si compound material in this paper.The median particle size of the Al-Si powder must be less than 5μm. The ball-milling technique was adopted to reduce the particle size of Al-Si powder. The result shows: the change in ball-milling speed affects the particle size of Al-50 Si powder greatly and the increase of rotating speed can facilitate powder fining and homogenization. By determining other process parameters, it is found the ball-milling time is the major factor affecting the particle size. As the ball-milling time extends, the particle size reduces. Compared to the dry milling process, the alcohol wet milling process can improve the fine powder output, reduce particle size distribution range, avoid powder agglomeration and get good homogenization. Less particle size also result in higher density and less Si phase particle size in Al-50 Si compound. In the following condition, namely the ratio of grinding media to material is 5:1, the rotating speed 350 rpm and ball-milling time 20 hrs, the median particle size of Al-50 Si powder is 4.64μm.