CN-115274000-B - Alloy component optimization design method for additive manufacturing

CN115274000BCN 115274000 BCN115274000 BCN 115274000BCN-115274000-B

Abstract

The invention discloses an alloy component optimization design method for additive manufacturing, and belongs to the technical field of additive manufacturing. The method for optimizing the design of the alloy components for the additive manufacturing is characterized in that the numerical range of the content of the alloy components is expanded to comprise all the content of the existing alloy components on the basis of the existing alloy components, the thermodynamic calculation and the high-throughput calculation are combined, the proper alloy components are optimized according to the thermal cracking criterion of the strain rate based on thermal cracking sensitivity indexes, alloy powder for the additive manufacturing is prepared according to the optimized alloy components, the laser additive manufacturing is carried out, microstructure observation and performance test are carried out on samples after the additive manufacturing, and component optimization conforming to actual alloy performance is selected. According to the invention, the optimal design of alloy components is taken as a main influencing factor, thermodynamic software and computer language are combined to optimize the components to reduce the thermal cracking sensitivity of the additive manufacturing alloy through thermal cracking sensitivity indexes, and the method is beneficial to industrial mass production and popularization and application.

Inventors

YIN HAIQING
WU LINGZHI
ZHANG CONG
ZHANG RUIJIE
JIANG XUE
WANG YONGWEI
QU XUANHUI
SU JIE
LIU GENG

Assignees

北京科技大学
北京科技大学

Dates

Publication Date: 20260421
Application Date: 20220614
Priority Date: 20220601

Claims (7)

1. The method is characterized in that the method expands the content numerical range of the alloy components to include all the content of the existing alloy components on the basis of the existing alloy components, optimizes the proper alloy components according to strain rate thermal cracking criteria based on thermal cracking sensitivity indexes by combining thermodynamic calculation and high-throughput calculation, prepares alloy powder for additive manufacturing according to the optimized alloy components, performs laser additive manufacturing, performs microstructure observation and performance test on samples after additive manufacturing, and selects component optimization conforming to actual alloy performance; The range of the content values of the alloy components is expanded to comprise all the existing alloy component contents by the upper limit and the lower limit of the content values of the alloy components in national standards; The combined thermodynamic calculation and the high-flux calculation are that a Scheil-Gulliver solidification curve between solid phase fraction and temperature is obtained through the high-flux calculation by combining thermodynamic software Thermo-Calc and Python languages, and data of a solid phase fraction fs=0.9-0.99 interval on the curve is output.
2. The method for optimizing design of alloy components for additive manufacturing according to claim 1, wherein the combination of thermodynamic software Thermo-Calc and Python languages is achieved by calling Thermo-Calc software according to a program written in Python language, and combinations of different element contents are calculated sequentially according to step sizes.
3. The method for optimizing design of alloy components for additive manufacturing according to claim 1, wherein the thermal cracking sensitivity index is based on the fact that data output of a solid phase fraction fs=0.9-0.99 interval section on a curve is subjected to batch processing, the temperature on the ordinate is changed to +273.15 to obtain Kelvin temperature (K), the solid phase fraction on the abscissa is subjected to evolution, the evolution is performed on the Kelvin temperature, the derivative value is obtained on the solid phase fraction after the evolution, absolute values are sequentially obtained on the derivative values, the solidification thermal cracking sensitivity index meeting requirements can be obtained, and the obtained solidification thermal cracking sensitivity index is averaged within the solid phase fraction fs=0.9-0.99 range.
4. The method according to claim 3, wherein the strain rate thermal cracking criterion is that interaction force between dendrite grain boundaries is considered, and when the solid phase fraction is close to 1, the tearing force of the liquid film is larger than the sum of mutual growth and liquid filling between grains, and cracks start to initiate.
5. The method for optimizing the design of the alloy composition for additive manufacturing according to claim 1, wherein the alloy powder for additive manufacturing is an alloy powder prepared from an alloy ingot of the alloy composition, or is a powder prepared by mixing elemental metals or alloy powders according to a calculated content ratio.
6. The method of optimizing design of alloy composition for additive manufacturing according to claim 1, wherein the calculated data amount of the high-throughput calculation exceeds 3.0 x 10 12 sets.
7. The method for optimizing design of alloy components for additive manufacturing according to claim 1, wherein the laser additive manufacturing process is characterized in that the laser power is 200-300W, the scanning speed is 800-1000mm/s, the scanning interval is 100-120 μm, the layer thickness is 20-40 μm, the scanning strategy is Z-shaped scanning, and the energy density is 60-120J/mm 3 .

Description

Alloy component optimization design method for additive manufacturing Technical Field The invention belongs to the technical field of additive manufacturing, and relates to an alloy component optimization design method for additive manufacturing. Background The additive manufacturing technology has the advantages of short manufacturing period, near net forming, excellent mechanical property, strong structural adaptability and large design freedom degree, has obvious advantages on the forming of complex precise structures and difficult-to-process material components compared with the traditional technology, can process various metals, such as various alloys of aluminum alloy, titanium alloy, stainless steel, high-entropy alloy and the like, and is widely applied due to good processing performance and high reliability. However, in the additive manufacturing process, the quality of the formed part is often affected by solidification defects such as thermal cracks, on one hand, the process conditions are required to be continuously improved, and on the other hand, the alloy components in the additive manufacturing are required to be optimized again, so that the thermal cracking sensitivity is reduced. Chinese patent CN112570732a discloses a method for reducing thermal cracking sensitivity of a nickel-based superalloy manufactured by laser additive, which is to optimize technological parameters of laser additive, and component optimization is not to adjust the content based on the existing element components, but to additionally add pure zirconium powder with mass fraction of 1.5% and pure aluminum powder with mass fraction of 0.5%, and is only applicable to nickel-based superalloy, but not to aluminum alloy and other alloys. Chinese patent CN108994304a discloses a method for eliminating cracks in additive manufacturing of metal materials and improving mechanical properties by sequentially performing stress relief annealing and spark plasma sintering treatment on the additive manufactured formed part, and does not consider adjustment of the component content of the metal material to reduce the cracks in additive manufacturing, but gives a heat treatment, which obviously consumes much higher cost than adjustment of the component content of the metal material. Chinese patent CN111235564A discloses a special high-temperature alloy component design method for additive manufacturing, which aims at high-temperature alloys and is obviously not suitable for aluminum alloys and other alloys, alloy components selected by an orthogonal design method are limited by the level adopted by experiments, and as the influence of hot cracking sensitivity indexes on component selection is not considered, the influence is not considered in the selection basis of a plurality of groups of proper components optimized by using thermodynamic calculation software and an electronic vacancy number calculation method, and the selected components cannot reduce the hot cracking sensitivity of the high-temperature alloys and can not reduce the hot cracking sensitivity of the aluminum alloys and other alloys. Chinese patent CN110010210a discloses a multi-component alloy component design method based on machine learning and facing performance requirements, although a dataset is built, C2P and P2C models are built and trained according to historical data, a certain experience error exists in a mode of inputting target performance as input data to P2C to obtain initial design components, the relationship between the thermal cracking sensitivity index and the selection of components is extremely complex, the data required by machine learning is very much, the learning time is long, the accuracy verification times are more, the selection efficiency of components for reducing thermal cracking sensitivity of superalloy, aluminum alloy and other alloys is low, and the cost is high. In summary, most of the methods for reducing the thermal cracking sensitivity in the prior art are optimizing the process parameters of laser additive, especially the laser process parameters and heat treatment, and the methods for reducing the thermal cracking sensitivity by component selection are considered, but the methods are only supplementary to the heat treatment, not the main technical means, and the methods for designing the components have a plurality of methods including orthogonal test design and machine learning, however, the methods have the defects of the method or the method, the cost is high, and the method is unfavorable for industrial mass production and popularization and use. Disclosure of Invention The invention aims to solve the technical problems that the mode of reducing the thermal cracking sensitivity in the prior art is realized mostly through laser process parameters and heat treatment of laser additive, and the laser process parameters are regulated and controlled in a separate mode, and the heat treatment and auxiliary component addition are als