| CuCrZr alloy has excellent thermal conductivity,electrical conductivity,hardness,high strength and high temperature characteristics,widely used in aerospace,machinery,chemical industry,transportation and other fields.With the rapid development of industry,the traditional CuCrZr alloy forming process can not meet the needs of complex parts processing gradually.Selective Laser Melting(SLM)is a kind of additive manufacturing process which can directly form metal parts,which can directly form complex structural parts.Porous structure is a typical lightweight structure.Combined with the excellent properties of CuCrZr alloy,it is of great significance to expand the application of copper alloys in aerospace and other fields.In this paper,CuCrZr alloy is used as the research material,the porous structure of CuCrZr alloy is formed by SLM technique to study the influence of forming process and post-treatment technology on its structural properties.The major work carried out and the conclusions obtained are as follows:(1)Study on forming process optimization and mechanical properties of CuCrZr alloy SLM.Based on the orthogonal experimental design criteria,laser power,scanning speed and scanning distance were selected as the influencing factors to design the orthogonal experimental table of three factors and four levels.Evaluation of mechanical properties through compression tests.The study shows that the laser power has the greatest effect on the platform stress,followed by the scanning pitch,and the scanning speed has the least effect on the platform stress.The mechanical properties of the two structures were optimal at the process parameters of laser power of 390 W,scanning speed of 600mm/s and scanning pitch of 0.1mm.(2)Analysis of deformation and failure mechanism of CuCrZr alloy porous structure.During the compression process,the deformation process of the sample was recorded by the camera and combined with the finite element analysis SP structural surface well shared the stress at the cell-cell junction,so that the structure did not collapse prematurely due to the weakness of the junction between the cells and the overall compression resistance increased.Since the diameter of the cell link is much smaller than that of the cell center,the stress concentration occurs in the rod-shaped region of the IWP structure.The finite element results were consistent with the actual experimental results.(3)Study on post-processing technology of porous structure of CuCrZr alloy formed by SLM.Plasma polishing and nitriding processes were studied on porous structure samples,which included the quality,surface morphology,microstructure and compressive mechanical properties of CuCrZr alloy porous structure parts,the effects of different polishing times on the porous structure properties of CuCrZr alloy were studied.Research shows that plasma polishing can effectively remove the surface adhesion particles of CuCrZr alloy samples with porous structure.With the continuous improvement of polishing time,the performance of the sample also changes.In addition,nitriding technology can also effectively improve the mechanical properties of the porous structure sample.(4)Study of the bending properties of SLM formed CuCrZr alloy sandwich structures.The SP sandwich structure and IWP sandwich structure were designed based on the TPMS method and their flexural performance in the printed state and flexural performance under different plasma polishing times were tested by quasi-static three-point bending experiments.It was shown that the flexural performance of TPMS sandwich structure of CuCrZr alloy was related to its shape,the SP structure had better flexural performance.The bending deformation collapse mechanism was analyzed by Abaqus finite element analysis,and the two structures exhibited the same deformation mechanism,the SP sandwich structure and IWP sandwich structure damage was shown as TPMS core top + top panel damage. |
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