Papers by Author: Yi Yi Tao

Abstract: In recent years, significant progress has been made with in-deep application of piezoelectric harvesting energy technology. To make the technology development more convenient, a comprehensive review on application of piezoelectric harvesting technology is made in the paper. Piezoelectric harvesting devices as power source from vibration, human motion and so on are expounded. The technology would bring fast increasing in systems of micro wireless sensor, integrated systems and self-power MEMS.

Abstract: In recent years, significant progress has been made with in-deep application of piezoelectric harvesting energy technology. To make the technology development more convenient, a comprehensive review on application of piezoelectric harvesting technology is made in the paper. Piezoelectric harvesting devices as power source from vibration, human motion and so on are expounded. The technology would bring fast increasing in systems of micro wireless sensor, integrated systems and self-power MEMS.

Abstract: The relationships among the n, ap , and f of the SiCp /Cu composite material produced by powder metallurgy and extrusion have been investigated. The cutting force F of this material is also discussed in this paper by the measuring of the three cutting factors of n, ap, and f, applying the dislocation theory and the electron microscope analysis of the cutting surface and sub-surface. The differences are analyzed between the SiCp/Cu composite materials, QSn6-6-3. H59-1and the copper cutting surface and the sub-surface. The forming of mechanism, the function of SiCp in the cutting process and the influence on the cutting surface quality are also analyzed. This research has shown: because the SiCp particles prevent the dislocation moving, the dislocation groups are formed on the SiC/Cu interface, and the stress concentration is produced, the typical brittle separation appears in the SiC/Cu composite material cutting process. In addition, the cutting force increases with the depth of cut and feed increasing and decreases while the cutting speed increases.

Abstract: The SiCp/Al composites reinforced by SiC particles with various sizes and contents were prepared by cold compacting and subsequent hot extruding. The mechanical and wear properties of the compositions were investigated and the relevant mechanisms were discussed. It has been shown that the tensile strength and wear resistance increases with increasing SiCp content. SiC particles have a remarkable reinforcing effect on matrix Al. The composite with larger SiCp size (14μm) possesses better wear resistance than that with smaller SiCp size (130nm).

Abstract: The machining performance of porous NiTi shape memory alloys prepared using powder metallurgical production technique has been investigated experimentally in the grinding operation. Grinding force ratio, specific grinding energy, surface characteristics were detected. The result reveals that, much difference of grinding characteristics exists among three kinds of NiTi alloy because of the pore rate and the mechanical performance induced by TiH2. Under the experimental conditions, the integrated effects of predominant plastic flow and slight brittle fracture were taken for porous NiTi alloy during grinding. Additionally, the grinding parameters should be chosen carefully, otherwise the surface quality deteriorates and even the microcrack perhaps appears.