程宗辉,陈云鹏,舒送,等.激光熔化沉积钛合金-高熵合金梯度材料组织演变研究[J].精密成形工程,2024,16(4):129-137. CHENG Zonghui,CHEN Yunpeng,SHU Song,et al.Microstructure Evolution of Titanium Alloy-High Entropy Alloy Gradient Material by Laser Melting Deposition[J].Journal of Netshape Forming Engineering,2024,16(4):129-137. |
激光熔化沉积钛合金-高熵合金梯度材料组织演变研究 |
Microstructure Evolution of Titanium Alloy-High Entropy Alloy Gradient Material by Laser Melting Deposition |
投稿时间:2023-12-12 |
DOI:10.3969/j.issn.1674-6457.2024.04.016 |
中文关键词: 梯度材料 激光熔化沉积 钛合金 高熵合金 微观组织 |
英文关键词: gradient material laser melting deposition titanium alloy high entropy alloy microstructure |
基金项目:国防基础科研项目(JCKY2022605C004);中国博士后科学基金(2023M730824) |
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中文摘要: |
目的 研究钛合金-高熵合金梯度材料不同位置沉积层的微观组织形貌及力学性能演变规律。方法 采用激光熔化沉积的工艺制备了钛合金-高熵合金梯度材料,并建立了有限元仿真模型来辅助分析。研究对象为TA15基板上单道多层的梯度沉积层,在设计梯度材料成分时,相邻梯度的材料比例变化量为10%(质量分数),TA15钛合金的质量分数由100%逐渐降低至0%,AlNbTiVZr的质量分数逐渐增大。基于实验对有限元模型进行了一定程度的简化处理,通过热物性参数计算软件和经验公式获取了梯度成分材料的热物性参数,进行了单层单道激光熔化沉积实验以完成热源校核,在与实验相同的工艺参数下计算了温度场并进行了分析。结果 在一层一冷的冷却策略下,多层沉积仍存在一定的热累积现象,沉积15层后,沉积层中部的温度峰值基本保持在2 489 ℃,根据循环曲线,沉积层中部的重熔范围超过1/2。结论 随着高熵合金含量的增加,组织由细小等轴晶、胞状晶和柱状晶转变为多边形晶粒,V、Nb等β稳定元素的增加和Al等α稳定元素的减少抑制了组织中针状α相的形成,V、Nb等元素在晶界产生了明显偏析现象并逐渐增多,抑制了晶粒生长且增强了细晶强化作用,显微硬度随之增大。 |
英文摘要: |
The work aims to study the microstructure morphology and mechanical property evolution of titanium alloy-high entropy alloy gradient material deposition layer at different locations. Titanium alloy-high entropy alloy gradient materials were prepared by laser melting deposition, and a finite element simulation model was established to assist the analysis. The research focused on the single-track multi-layer gradient deposition layer on a TA15 substrate. During the design of the gradient material composition, the material proportion change of adjacent gradients was 10%. The mass fraction of TA15 titanium alloy gradually decreased from 100% to 0%, and the mass fraction of AlNbTiVZr gradually increased. The finite element model was simplified to some extent based on experiments. The thermal properties of the gradient composition materials were obtained by thermal property calculation software and empirical formulas. Single-layer single-track laser melting deposition experiments were conducted to validate the heat source, and the temperature field was calculated and analyzed by the same process parameters as the experiments. The results showed that under a one-layer one-cooling strategy, there was still a certain heat accumulation in multi-layer deposition. The temperature peak in the middle of the deposition layer remained around 2 489 ℃ after fifteen layers, and according to the cyclic curves, the remelting range in the middle of the deposition layer exceeded half. With the increase of high entropy alloy content, the microstructure transforms from fine equiaxed grains, cellular grains, and columnar grains into polygonal grains. The increase of β-stabilizing elements, such as V and Nb, and the decrease of α-stabilizing elements, such as Al, inhibit the formation of needle-like α phase in the microstructure. V, Nb, and other elements exhibit significant segregation at grain boundaries and gradually increase, inhibiting grain growth and enhancing the strengthening effect of fine grains, resulting in an increase in microhardness. |
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