Papers by Author: Jun Wei Cheng

Abstract: Heat treatment process of 31Mn2SiREB cast steel used in crawler plates is directly quenching at 1050°C after casting. The reasonableness of the process needs to be surveyed. In this paper, the effect of quenching temperature on mechanical properties was studied, and the micro-area composition and micro-hardness at different quenching temperature were investigated. The results show that tensile strength and impact energy increase observably with the elevating of quenching temperature. With the increase of quenching temperature, the fluctuations of micro-hardness and chemical composition at different micro-areas become obviously small. This means that the relatively homogeneous structure and composition can be acquired in higher temperature. The as-cast microstructure is extremely uneven, so pre-treatment process of normalizing or diffusion annealing ought to be carried out before quenching treatment, and quenching temperature should not be too high.

Abstract: Micro-electromechanical systems is called MEMS for short, it is the product of mutual integration for the micro-electronics and micro-mechanics, which covers mechanical, electrical, physical, biological and other modern technology. MEMS packaging is a key technology that has been developed based on electronic package technology. In order to strengthen the development of packaging process of MEMS, in particular, which are low cost, materials and packaging technology and has an ideal effect. The characteristics of MEMS packaging technology based on MEMS technologies are introduced, and the future development tendency and application of MEMS device packaging are previewed in this dissertation.

Abstract: Nanotechnology has become a comprehensive high-tech subject, and will be the core in the next technological revolution times. With the flourishing development of nanotechnology, it is clear that its research and development have become the hot spot these days for the international scientific community and the engineering community. In this paper, content and development of nanotechnology are discussed in details, as well as the analysis of its application in the field of micro-mechanical, non-friction micro-nano-bearings, the new metal-ceramic nano-tools, nano-magnetic fluid sealed in the ultra-fine grinding machine, etc. And looks forward to applying the nanotechnology in our country.