Research On The Preparation Of Fine-grain Copper T2 And The Precision Volume Of Micro Forming Of Micro Gear

Over the past decade, with the rapid development of Micro-electronics technology and micro electro-mechanical system, the requirement of micro parts becoming increasing in electronic industries, medical, aerospace, new energy and other areas. However, The mature macroscopic theory can,t be directly applied to the plastic forming process of micro parts because of size effect which restrained the development of micro manufacturing industry. The volume of micro forming become the most important research with high efficiency, low cost, low material loss, low pollution, high-precision, etc. The article focuses on exploratory research in the application of fine-grained materials in the field of the volume of micro-forming, the main contents are as follows:Simulates the ECAP process by DEFORM-3D software, and obtains the deformation load, the stress field, the velocity field and the distribution of equivalent strain field, the results showed that: the deformation load first rise, then remained stable, and finally decline slowly during the ECAP process; It is always the largest for the equivalent force around the corner of the mold, and the maximum equivalent stress value is also increasing with the increasing of the extrusion passes, but the rate of increasing gradually decreases; the flow rate of material near the outside of the mold is greater than the inside of the material in the zone where material cross the severe deformation; the equivalent strain increased rapidly when the material goes through the corner of the mold, and then remained unchanged after the corner; the total equivalent strain by the first pass of 1.33 to the eight pass of 11.1 with the increasing of the pressing times.Designs and manufactures the ECAP mold for which used the preparation of fine grained copper T2 material, the samples were extruded for eight passes in BC path, and annealed for the extruded samples in order to stress annealing, and study the impact on microstructure and mechanical properties of the material by extrusion passes and stress relief annealing, the results show that: the strength and elongation of the material gradually increased with the increasing of extrusion passes, The tensile strength raised to 372.6MPa and the elongation raised to 56.7% after squeezing eight times and stress annealing,; by microscopic metallurgical and EBSD experiments show: the grain was significantly refined with the increasing of extrusion passes,, through the state of original 15.31 μm refine to the No.8 passes 2.77 μm.Study the influence of which the grain size and width dimensions to the material filling performance, the results show that: the filling performance of materials become weaker with the decreases of the width dimensions and the smaller the grain size, the better of the filling properties of materials, and explained the conclusions by establishment of an experimental model of polycrystalline micro molding.Use the fine-grained copper T2 of the No.8 passes annealed to form four different specifications teeth with modulus of 0.1mm, 0.2mm, 0.3mm and 0.4mm, teeth of ten by the method of combining the finite element with practical experiments, and observed and analyzed the quality of micro gear by the scanning electron microscopy, The results show that: the quality of micro gears is good; the fine-grained materials were used in forming the area in some small feature size has unique advantages compared to conventional materials in volume micro-forming.