Design And Simulation Analysis Of Hot Forging Die Based On FGM Surface Coating

In hot forging production, hot forging dies have to bear the high temperature and mechanical shock from the workpiece. And the poor working conditions leading to mold bore surface departments are easy to become phase transformation, deformation, cracks or defects. Therefore, if we deal with the die surface to improve the performance of the die surface against high temperature,we can increase the capacity of the die in bearing heat and extend the die life. Recently,a new method called gradient coatings appares in the die surface treatment.In this paper, we focus on the forging dies working condition and load characteristics. Conclusion comes that in a certain mechanical impact the the main factor affecting dies life is the high temperature.And in the die bore surface temperature fluctuation zone, the dies are bearing the maximum heating load and are most easy to form types of defects and injury. Therefore, we can use the thermal protection type of functionally gradient material(FGM) as the die surface coating.This material can effectively improve heat resistance of the die and its ability to prevent damage.This article reaearchs on the gradient functional materials development and application and makes a detailed study of gradient material design, preparation and performance evaluation.We also investigate the elastic modulus, Poisson's ratio, thermal conductivity and thermal expansion coefficient how to effect the performance of the hot forging die Then we master the functionally gradient material types and characteristics and clearly the feasibility of the use of in the die.Finite element software DEFORM can effectively simulate the forging process and analysis the physical field.We choose Ti-6A1-4V metal materials and ZrO2 ceramic material composite to a die coating as the die coating surface,design the functionally graded layers and components, calculate the gradient of the physical parameters of materials,build the model and design the whole production process.Through software simulation and analysis,we get the conditions of temperature field and stress field.We also obtain the accurate temperature field and the stress field curve and the changes in the physical field. By the comparison of the homogeneous forging die and the gradient coating,we find that the gradient coating play a significant role in reducing the whole die temperature and heating load and also the equivalent internal stress.After the simulation experiments,we come to a conclusion that the gradient coating can largely improve the die performance in high temperature. So functionally gradient material are available in the hot forging die.For the ideal gradient material are uniform and smooth in its material composition and performance. Therefore, this material will be more perfect on reducing structural stress and match compatibility. It is the direction of the gradient material gradual improvement and development.