| Additive Manufacturing technique(commonly known as 3D printing) is an incorporate process that mixes together organically by laser metallurgy or curdle rapidly High- performance material preparation and heap up Parts manufacturing directly layer-by-layer. And this process made the Three-dimensional digital manufacture implement very easy, especially suitable for difficult-to-machine materials, the development and production of complex structure parts, high utilization rate of raw materials and manufacturing products without props and moulds. It responds fast and conforms to the concept of green manufacturing. Of course, can Additive Manufacturing develops quickly and applies of engineering, depends on the understanding of the understanding of the fundamental problem. Including the behavior of curdling the moving molten pool, artifacts of the grain morphology, evolvement rule of the innerstress, formation mechanism of the internal metallurgical defects and mechanical behavior. To clarify these issues, a large number of experiments are needed, but the use of ANSYS simulation software can simplify this process, and has a prediction and guidance influence on this process.This article in view of the Additive Manufacturing process of hollow blade, and analyze it by thermal elastic analysis, building the finite element model of temperature field and stress field by Ansys, simulating the process of deposit growth of cladding layer by birth-death element and moving heat source technology. Through the indirect coupling to simulate temperature field and stress field of the DZ125 L Additive Manufacturing process of hollow blade evolution process. And analyzing the microstructure of the Additive Manufacturing Nickel base alloy hollow blade by SEM and EBSD.The simulation of the temperature field of Additive Manufacturing of Nickel base alloy hollow blades results show that: the start stage, Molten pool is small, cooling rate was about 772.4℃ / s, the temperature gradient is higher 3.42 x 106℃ / m or so, with the increase of the cladding layer, the fusion zone expanded, molten pool cooling rate decreases, and reduce the temperature gradient, the last layer of cooling rate is about 593.9℃ / s, the molten pool temperature gradient was 2.215 x 106℃ / m. Forming the circumferential temperature gradient in the process of a maximum of 8.83 x 104℃ / m is always less than the longitudinal temperature gradient maximum 4.06 x 106℃ / m. At the end of the forming, because of the influence of the blade shape, the head and tail of the blade cooling significantly lower than other location. On the whole, although the age of cladding layer increases and leaf surface heat transfer function, but the direction of heat radiation did not change. It radiating from top to bottom, from the single direction of the molten pool to the base, the heat dissipation characteristics of directional solidification.The simulation of the stress field of Additive Manufacturing of Nickel base alloy hollow blades results show that: Due to the Cooling and restraint of the base to the cladding layer and the heating of the bath to the last cladding layer has the effect of stress release, the Increasing material manufacturing process of hollow blade showed a gradient distribution from high to low along the height direction. So the root of the leaf has the largest effect force. Due to the impact of the blade shape, tail and head of the blade have stress concentration of phenomenon on other parts.Results of microstructure show that: Hollow blade made by Additive Manufacturing is columnar crystal, the average size has increased with the increase of cladding layer. And the grain orientation difference angle is also gradually transformed to less than 5, texture is also transformed from the cube textured {001}<100> to the other two kinds of textures {001}<120> and {001}<230>. |
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