The numerical thermal mechanical simulation of radial forging process of C45 steel stepped shaft with GFM forging machine was carried out by three dimensional finite element method DEFORM 3D. According to effective plastic strain, mean stress and mean plastic strain distribution of the radial forging process, the forging penetration efficiency (FPE) was studied throughout. The results show that: effective plastic strain in the center of the forging is never be zero; The mean stress in the center of the workpiece is proposed to describe hydrostatic pressure in this paper. There is compressive strain layer beneath the surface of the workpiece, while there is tensile strain layer in the center of the forging. These studied results could be a valuable reference for designing the similar forging operations.

SiC films were prepared by HFCVD technique on (111) Si substrate. The composition and the structure of the films were investigated using EDX, XRD and transient fluorescence. Results indicated the films deposited were nanocrystalline and the calculation of the grain size gave a further confirmation. PL measurement of the present films showed that there existed a strong ultraviolet emission at room temperature.

A new micro-forming method, combining a metal’s super-plastic behavior with hot extrudsion technology, has been developed for manufacturing micro-gear from brass H62. The micro-gear, which modulus m = 0.125mm, pressure angle α = 20°, number of teeth z = 6, tip diameter d = 1mm, was selected and its dies were designed with a better die approach angle based on the DEFORM-3D FEA simulation results of the hot extrusion process. Finally the micro-gear was successfully hot extruded at 650°C from blank Φ3mm×3mm with extrusion ratio about 17. A good dimensional accuracy for micro-gear was obtained by using this hot extrusion technology. In the special die set, the split die structure was designed, and the special die materials were chosen, such as the pressure ram was made of tungsten carbide, and the other dies were made of mold materials 4Cr5MoSiV1.

Gears are very important and widely used driving components in mechanical instruments, and the demands of micro-gears are increasing more and more active as the MEMS technology develops in recent years. In this paper, a brass micro gear, which modulus m = 0.125 mm, pressure angle α = 20°, number of teeth z = 6, addendum circle diameter d = 1 mm, hot extruded from brass H62 billet with size Φ3×3 mm at 650°C was studied by experimental method. The microstructure of the micro gear was observed by scanning electron microscope and optical microscope, and the conclusions are as follows: the fiber flow lines within the micro-gear were formed by the extrusion, so that the anisotropic mechanical properties of the micro-gear was happened; The tissue distribution of micro-gear was that, the surface of the gear is almost entirely α-phase, while the internal part of the gear was the mixture of α-phase and β-phase, because the α-phase with lower hardness flowing outward to the surface of the gear during the extrusion process.

The experimental design and implementation, as well as the fatigue life test of the steel C45 grooved axis warm surface rolling, have been carried out in this paper. The focus of the experiment is to study the effect of the different amount of rolling reduction and surface temperature on the fatigue life of the specimen axis.The experimental specific condition is at different temperature 20°C, 100°C, 200°C and 300°C with surface rolling reduction 0.03 mm, 0.06mm, 0.10mm, and 0.15mm respectively. The simulation results showed that the warm surface rolling process can significantly improve the fatigue life of the specimen axis; and there exist a corresponding optimum rolling reduction, in this case the fatigue life of the specimen axis achieves maximum, at different warm rolling temperatures. Finally the preferred processing parameter at 300°C with 0.15mm surface rolling reduction is obtained. This study has certain reference value for steel C45 the crankshaft undercut surface rolling.