A method for evaluating the metallurgical quality of a powder near-net shaped thin-walled complex component

Abstract

This invention belongs to the field of powder metallurgy hot isostatic pressing technology, specifically relating to a method for evaluating the metallurgical quality of near-net-shape thin-walled complex components formed by powder metallurgy. The technical solution is as follows: A part blank drawing is prepared based on the part design drawing. Then, while maintaining the main shape and key features, the overall dimensions are proportionally reduced to obtain a simulated test piece blank drawing. Finite element simulation is used to perform finite element analysis on the thin-walled complex component and the simulated test piece under the same conditions, establishing quantitative evaluation indicators. Based on the comparative analysis results, the structure of the simulated test piece is optimized iteratively to determine its structure and dimensions. The simulated test piece and the thin-walled complex component are then subjected to powder metallurgy hot isostatic pressing and heat treatment in the same furnace. The microstructure and performance of the simulated test piece are tested according to product acceptance standards to evaluate the metallurgical quality of the thin-walled complex component. This invention can significantly improve the accuracy of quality evaluation and reduce testing costs.

Description

Technical Field

[0001] This invention belongs to the field of powder metallurgy hot isostatic pressing technology, specifically relating to a method for evaluating the metallurgical quality of near-net-shape thin-walled complex components formed by powder metallurgy. Background Technology

[0002] Powder metallurgy hot isostatic pressing (HIP) technology, as an advanced near-net-shape manufacturing process, offers significant advantages in the fabrication of complex components from titanium alloys and high-temperature alloys. This technology, by simultaneously applying high temperature and high pressure, enables the complete densification of metal powder in an inert gas environment, allowing for the fabrication of parts with complex geometries. This significantly reduces subsequent machining allowances and shortens the overall processing cycle. Compared to traditional forging processes, HIP components exhibit lower internal stress, more uniform microstructure, and isotropic mechanical properties. These superior material properties have led to their widespread application in high-tech fields such as aerospace, playing a crucial role, particularly in the manufacture of key components for aero-engines.

[0003] In the manufacturing and use of aero-engines, to ensure flight safety, rigorous quality assessments of key load-bearing components, including their microstructure and performance, are essential. For conventionally forged parts, metallurgical quality assessments can typically be conducted through body dissection or test rings. However, for near-net-shape powder metallurgy hot isostatic pressing (HIP) components, due to their small or even nonexistent machining allowances, and their generally thin wall thickness and complex shapes, it is difficult to obtain satisfactory physicochemical samples through body dissection. Especially for large-sized parts delivered in small batches, body dissection costs are often prohibitively high, making it economically unreasonable. Currently, the industry commonly uses cylindrical furnace-fed test bars for metallurgical quality assessment of complex near-net-shape powder metallurgy components. However, this method has significant technical drawbacks: because the furnace-fed test bars and the actual powder metallurgy parts differ greatly in shape and size, the shrinkage and deformation patterns of the powder during HIP are inconsistent, ultimately resulting in significant differences in the mechanical properties of the test bars compared to the actual parts, leading to poor representativeness. The inaccuracy of this evaluation method poses a significant safety hazard to the application of powder metallurgy hot isostatic pressing near-net-shape forming parts in aero engines. Summary of the Invention

[0004] This invention provides a metallurgical quality assessment method for near-net-shape thin-walled complex components made of powder, which can significantly improve the accuracy of quality assessment, save material usage, and reduce testing costs.

[0005] The technical solution of the present invention is as follows: A method for evaluating the metallurgical quality of near-net-shape thin-walled complex components using powder metallurgy is proposed. First, a blank drawing of the component is created based on its design drawing. Then, while maintaining the main shape and key features of the component, the overall dimensions are proportionally reduced to obtain a simulated test piece blank drawing. Next, finite element simulation analysis is performed on the thin-walled complex component and the simulated test piece under the same conditions to establish quantitative evaluation indicators. Based on the comparative analysis results, the structure of the simulated test piece is optimized iteratively to determine its structure and dimensions. Finally, the simulated test piece and the thin-walled complex component are subjected to powder metallurgy hot isostatic pressing and heat treatment in the same furnace. The microstructure and properties of the simulated test piece are tested according to product acceptance standards to evaluate the metallurgical quality of the thin-walled complex component.

[0006] Furthermore, the metallurgical quality assessment method for near-net-shape thin-walled complex components made of powder specifically includes the following steps: 1) Based on the part design drawings of thin-walled complex components, extract key geometric feature parameters, including main contour dimensions, minimum wall thickness, and key fillet radii, to determine the part blank drawing for powder metallurgy hot isostatic pressing. 2) Based on the part blank drawing, its complex structural features are appropriately simplified. The simplification principle is to keep the main shape and key stress characteristics unchanged, and to reduce the overall size proportionally, with the scaling ratio controlled within the range of 0.3-0.7 times. In order to meet the requirements of subsequent physical and chemical sample sampling, the wall thickness of the key testing area is appropriately increased, with the increase controlled within the range of 1.5-2 times the original wall thickness, to determine the preliminary blank drawing of the simulated test piece. 3) Based on the type of powder alloy, obtain accurate thermophysical parameters of the material through experimental testing or material databases, including coefficient of thermal expansion, thermal conductivity, and high-temperature rheological stress; 4) Based on the obtained material thermophysical parameters, an advanced constitutive model including powder particle rearrangement and diffusion creep mechanism is established to construct a high-precision finite element analysis model; 5) Using professional finite element software, under the same hot isostatic pressing process conditions, including temperature curves, pressure curves, and holding time, synchronous finite element simulation is performed on the blanks of thin-walled complex components and the blanks of simulated test pieces. 6) Conduct multi-dimensional comparative analysis of the simulation results, focusing on the similarity of shrinkage deformation law, density distribution, strain field, stress field and temperature field, and establish quantitative evaluation indicators. Among them, the deviation of dimensional deformation should be controlled within 3%, the density deviation should not exceed 0.5%, and the similarity of temperature field and strain field distribution should reach more than 95%. 7) For areas that do not meet the evaluation index requirements, the structural parameters of the simulated test piece are optimized and adjusted accordingly to complete the design iteration and finally determine the structure and size of the simulated test piece; 8) The simulated test piece and the thin-walled complex component are subjected to hot isostatic pressing and heat treatment in the same furnace. The microstructure and properties of the simulated test piece are tested according to the product acceptance standards to evaluate the metallurgical quality of the thin-walled complex component.

[0007] The beneficial effects of this invention are as follows: This invention enables low-cost and high-accuracy metallurgical quality assessment of near-net-shape powder-formed parts. By establishing a precise finite element model, this invention numerically simulates and compares the deformation behavior, densification process, and microstructure evolution of actual parts and simulated test pieces under the same hot isostatic pressing (HIP) conditions. Based on the simulation results, the geometric shape and dimensional parameters of the simulated test piece are optimized to ensure that its shrinkage deformation during HIP is highly consistent with that of the actual part. Compared to traditional cylindrical furnace-fed test bars, this optimized simulated test piece is closer to the actual part in terms of microstructure and mechanical properties, significantly improving the accuracy of quality assessment. Furthermore, compared to directly dissecting the actual part, using simulated test pieces can greatly save material usage and reduce testing costs, making it particularly suitable for quality assessment of small-batch, high-value aerospace components. This method guides the design of test specimens through numerical simulation, ensuring both the reliability of the evaluation results and economic efficiency. This finite element analysis-based simulation test specimen design method is expected to be applied to a wider range of thin-walled complex components, establishing new technical standards for the quality assessment of key components in the aerospace field. Detailed Implementation

[0008] A method for metallurgical quality assessment of near-net-shape thin-walled complex components made of powder metallurgy, comprising the following steps: 1) Based on the part design drawings of thin-walled complex components, extract key geometric feature parameters, including main contour dimensions, minimum wall thickness, and key fillet radii, to determine the part blank drawing for powder metallurgy hot isostatic pressing. 2) Based on the part blank drawing, its complex structural features are appropriately simplified. The simplification principle is to keep the main shape and key stress characteristics unchanged, and to reduce the overall size proportionally, with the scaling ratio controlled within the range of 0.3-0.7 times. In order to meet the requirements of subsequent physical and chemical sample sampling, the wall thickness of the key testing area is appropriately increased, with the increase controlled within the range of 1.5-2 times the original wall thickness, to determine the preliminary blank drawing of the simulated test piece. 3) Based on the type of powder alloy, obtain accurate thermophysical parameters of the material through experimental testing or material databases, including coefficient of thermal expansion, thermal conductivity, and high-temperature rheological stress; 4) Based on the obtained material thermophysical parameters, an advanced constitutive model including powder particle rearrangement and diffusion creep mechanism is established to construct a high-precision finite element analysis model; 5) Using professional finite element software such as DEFORM or ABAQUS, under the same hot isostatic pressing process conditions, including temperature curves, pressure curves, and holding time, perform simultaneous finite element simulation on the blanks of thin-walled complex components and the blanks of simulated test pieces. 6) Conduct multi-dimensional comparative analysis of the simulation results, focusing on the similarity of shrinkage deformation law, density distribution, strain field, stress field and temperature field, and establish quantitative evaluation indicators. Among them, the deviation of dimensional deformation should be controlled within 3%, the density deviation should not exceed 0.5%, and the similarity of temperature field and strain field distribution should reach more than 95%. 7) For areas that do not meet the evaluation index requirements, the structural parameters of the simulated test piece (such as wall thickness gradient, fillet radius, etc.) are optimized and adjusted accordingly to complete the design iteration and finally determine the structure and size of the simulated test piece; 8) The simulated test piece and the thin-walled complex component are subjected to hot isostatic pressing and heat treatment in the same furnace. The microstructure and properties of the simulated test piece are tested according to the product acceptance standards to evaluate the metallurgical quality of the thin-walled complex component.

Claims

1. A method for evaluating the metallurgical quality of near-net-shape thin-walled complex components formed by powder metallurgy, characterized in that, First, a blank drawing of the thin-walled complex component is prepared based on the part design drawing. Then, while keeping the main shape and key features of the part unchanged, the overall size is scaled down proportionally to obtain a blank drawing of the simulated test piece. Next, finite element simulation analysis is performed on the thin-walled complex component and the simulated test piece under the same conditions to establish quantitative evaluation indicators. Based on the comparative analysis results, the structure of the simulated test piece is optimized and iterated to determine the structure and size of the simulated test piece. Finally, the simulated test piece and the thin-walled complex component are subjected to powder hot isostatic pressing and heat treatment in the same furnace. The microstructure and performance of the simulated test piece are tested according to the product acceptance standards to evaluate the metallurgical quality of the thin-walled complex component.

2. The method for metallurgical quality assessment of near-net-shape thin-walled complex components according to claim 1, characterized in that, Specifically, the steps include the following: 1) Based on the part design drawings of thin-walled complex components, extract key geometric feature parameters, including main contour dimensions, minimum wall thickness, and key fillet radii, to determine the part blank drawing for powder metallurgy hot isostatic pressing. 2) Based on the part blank drawing, its complex structural features are appropriately simplified. The simplification principle is to keep the main shape and key stress characteristics unchanged, and to reduce the overall size proportionally, with the scaling ratio controlled within the range of 0.3-0.7 times. In order to meet the requirements of subsequent physical and chemical sample sampling, the wall thickness of the key testing area is appropriately increased, with the increase controlled within the range of 1.5-2 times the original wall thickness, to determine the preliminary blank drawing of the simulated test piece. 3) Based on the type of powder alloy, obtain accurate thermophysical parameters of the material through experimental testing or material databases, including coefficient of thermal expansion, thermal conductivity, and high-temperature rheological stress; 4) Based on the obtained material thermophysical parameters, an advanced constitutive model including powder particle rearrangement and diffusion creep mechanism is established to construct a high-precision finite element analysis model; 5) Using professional finite element software, under the same hot isostatic pressing process conditions, including temperature curves, pressure curves, and holding time, synchronous finite element simulation is performed on the blanks of thin-walled complex components and the blanks of simulated test pieces. 6) Conduct multi-dimensional comparative analysis of the simulation results, focusing on the similarity of shrinkage deformation law, density distribution, strain field, stress field and temperature field, and establish quantitative evaluation indicators. Among them, the deviation of dimensional deformation should be controlled within 3%, the density deviation should not exceed 0.5%, and the similarity of temperature field and strain field distribution should reach more than 95%. 7) For areas that do not meet the evaluation index requirements, the structural parameters of the simulated test piece are optimized and adjusted accordingly to complete the design iteration and finally determine the structure and size of the simulated test piece; 8) The simulated test piece and the thin-walled complex component are subjected to hot isostatic pressing and heat treatment in the same furnace. The microstructure and properties of the simulated test piece are tested according to the product acceptance standards to evaluate the metallurgical quality of the thin-walled complex component.