Research On The Related Factors Of The Performance Of Powder Hot Forging Parts

Powder metallurgy parts have been widely used in the field of mechanics, electronics, motors and automation. However, its technique leads to its non-close-packed products, which will have great influence on the function of these parts. Because the traditional technique cannot meet the need of the modern industry, it is necessary to find an effective way to solve this problem. The occurrence of the powder forging craft attracts overseas and domestic experts’ attention, for this craft combines the advantages of the powder metallurgy technique as well as precise forging technology and it can provide Fe-based powder metallurgy parts with high mechanical properties. Meanwhile, numerical simulation technology has gradually become a main modern research method on the precision plastic forming of powder metallurgy. Application of this technology can easily reproduce the effect of various parameters on the powder forging process, which provides a scientific basis for optimizing the powder forging technology and improving the accuracy and performance. Therefore, this thesis will made a careful study on the various parameters’influence on density and performance in the powder hot-forging process, as well as the forming process of powder hot-forging by finite element numerical simulation. The specific aspects are demonstrated as follows:1. This thesis will systematically analyze the influence of crucial factors (forging pressure and forging temperature) on the density and performance of the powder hot-forging parts, and design a simple and practical experimental apparatus to research the flow density of the preforms under different pressure and temperature. And then the law of the forging pressure and temperature influence on the density and mechanical properties will be concluded and the best forging pressure is573Mpa, the best forging temperature is1050℃.2. This thesis will build the relation model among forging pressure, temperature and relative density, and analyze the correlation between relative density and hardness. Meanwhile, it draws the curves about the relationship among the relative density, hardness and crush strength under the different conditions. The results show that the correlation analysis and graphs can be a good predictor of the mechanical properties of the powder forging different process conditions. 3. Based on the experimental research, the rigid-plastic finite element model of Thermo-mechanical coupled will be adopted to reproduce the parameters in the powder hot-forging forming process and carry out the simulation about the density forming process. And then, comparison of the results from the simulation and experiment is made to get an inosculation between the theory and practice, which will provide a valuable basis for the prediction of density deformation and determination of parameters in the powder hot-forging process.