Construction method of metal additive manufacturing solidification structure processing prediction map

Abstract

The invention discloses a construction method of a metal additive manufacturing solidification structure processing prediction map, which comprises an extraction method for numerical simulation of solidification parameters corresponding to all positions of a solidification front edge, an indexing processing method for microscopic observation of a grain morphology image result, a data pairing method betweenthe solidification front edge temperature gradient G and solidification speed R values obtained through numerical simulation and crystal grain morphology indexes obtained through experimental observation, and a method for obtaining a final solidification structure processing prediction map based on a solidification map drawn based on multiple groups of simulation and corresponding experimental results. The solidification diagram and the solidification structure processing prediction diagram drawn by the method better conform to the characteristics of the additive manufacturing process, and the obtained relevant result of the specific material is closer to the objective fact. In the implementation process, numerical simulation, image processing, computer language programming and other means are comprehensively utilized, mass data of experiments and simulation can be efficiently processed, and the result reliability is further improved by obtaining a large number of statistical results.

Description

technical field [0001] The invention relates to metal additive manufacturing technology, in particular to a method for constructing a solidification structure processing prediction map for metal additive manufacturing. Background technique [0002] At present, in the Metal additive manufacturing (MAM) process, the heat flow direction is roughly parallel to the layer-by-layer stacking direction, and the temperature gradient of the solidification front is large, so under the dominance of epitaxy and competitive growth characteristics, it is easy to form along the vertical direction. Coarse columnar crystal structure that grows in the same direction. [0003] As a common problem of MAM, the highly directional columnar grains not only cause the anisotropy of material properties, but also lead to the reduction of plastic toughness, damage tolerance and fatigue performance. [0004] Especially for superalloys with high crack sensitivity, the initiation and propagation of cracks a...

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Problems solved by technology

However, the existing problem is that, on the one hand, it is difficult to introduce material property values ​​that vary with temperature, such as thermal conductivity, specific heat, density, etc., and the calculated temperature field must deviate from the actual temperature field; on the other hand, although the finite element method Although the temperature change of material physical parameters can be considered, the influence of fluid convection on the temperature field and solidification conditions in a highly dynamic molten pool such as MAM cannot be involved.

Therefore, for the solidification map with high quantitative requirements, it is difficult to obtain objective and accurate temperature field and corresponding solidification parameters under the influence of multiple physical factors, whether it is analytical method or finite element numerical simulation.

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