Papers by Author: Ping Yi Guo

Abstract: For forging die fracture behaviors during the actual forging process of compactor grinding tooth, the fully forging process has been simulated based on FEM. Die stress changes and distributions were analyzed in details through two related simulation processes. The maximum load acting on the die which type is ideal rigid body predicted firstly. Then, the die stress can be obtained by the elastic-plastic analysis when the die bears maximum load. Results show that Local stress concentration beyond ultimate strength of material causes the fracture of lower die.

Abstract: During the preform design of blade body, the final forging process for blade body with different transverse cross section shapes coupled different twist angles along blade body are simulated by using DEFORM-2D finite element analysis software. The final forging quality effected by different perform structures of blade body are analyzed in details through comparing some key factors such as formability, deformation uniformity, loss of heat before deformation. The valuable references are obtained for further design of optimizing blade body shape.

Abstract: Ceramic coatings were prepared in situ on commercial pure Ti(CP-Ti) by Plasma Electrolytic Oxidation(PEO) technology in an environmental-friendly solution. The voltage–time responses were recorded during different PEO processes. For short treatment times, the formation processes of ceramic coatings follow a linear kinetics, while for longer times the kinetics departs from the linear behavior. The surficial morphology and composition of the coatings was studies by X-ray diffraction(XRD) and scanning electron microscopy (SEM). The acted electrochemical method was used to evaluate the corrosion of the coated samples in 1moll-1 NaOH solution. The potentiodynamic polarization curves of coated titanium samples and the untreated metal substrate show that the PEO coated titanium samples possess much higher corrosion potential and lower corrosion current than uncoated aluminum alloy. It is noticed that the passive current density of the samples decreased from 10-4A/cm2, for the titanium, to 10-7 A/cm2, for PEO coated titanium sample.