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Precipitation kinetics during non-linear heat treatment in Laser Additive Manufacturing

激光增材制造非线性热处理过程中的析出动力学

基本信息

批准号：
314594106
负责人：
Professor Dr. Eric A. Jägle
金额：
--
依托单位：
Institut für Werkstoffkunde (LRT-5)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/314594106?language=en
关键词：
Precipitation kinetics during non linear

项目摘要

Over the next years, Laser Additive Manufacturing (LAM) has the potential to spark a revolution in how complex and customised metallic parts are fabricated. However, research into alloys optimised or tailor-made for LAM remains scarce. The time-temperature profile experienced by alloys during LAM is very different from the one during conventional processing. Spike-like re-heating during the layer-by-layer deposition, i.e. the "intrinsic heat treatment", has a pronounced influence on the phase transformations occurring in precipitation-hardenable alloys employed in LAM. The objective of this project is to gain a fundamental understanding of the kinetics of precipitation during such strongly non-linear time-temperature profiles, with the ultimate goal of exploiting them for materials that are precipitation strengthened without the need for any post-manufacturing heat treatment. The material under investigation in this project will be a Ti- and Al-containing maraging steel that is expected to show rapid precipitation during the intrinsic heat treatment. Because the kinetics of precipitation during the intrinsic heat treatment is not accessible experimentally, the research programme will start by establishing a kinetic model for precipitation during linear heat treatment. It will be tuned to match the kinetics as determined from in-situ (calorimetry) and ex-situ (atom-probe tomography) experimental measurements. After a match between experiment and model has been reached, it will be employed to simulate precipitation during the non-linear heat treatment of LAM, thereby enabling an understanding of the process parameters that need to be adjusted to optimise the intrinsic heat treatment. The results of the simulations will be compared with atom probe tomography results. Additionally, the influence of chemical and thermal inhomogeneity occurring during LAM on the precipitation kinetics will be studied.

在接下来的几年里，激光增材制造（LAM）有可能引发复杂和定制金属零件制造方式的革命。然而，为LAM优化或定制的合金研究仍然很少。合金在LAM期间经历的时间-温度曲线与常规处理期间的时间-温度曲线非常不同。在逐层沉积过程中的尖峰状再加热，即“本征热处理”，对LAM中采用的可沉淀硬化合金中发生的相变具有显著影响。该项目的目的是获得在这种强烈的非线性时间-温度曲线的沉淀动力学的基本理解，与利用它们的材料，而不需要任何制造后的热处理的最终目标。本项目研究的材料是一种含Ti和Al的马氏体时效钢，预计在本征热处理过程中会出现快速析出。由于在本征热处理过程中析出的动力学无法通过实验获得，因此研究计划将从建立线性热处理过程中析出的动力学模型开始。它将被调整，以匹配动力学确定从原位（量热法）和异位（原子探针断层扫描）实验测量。在实验和模型之间的匹配已经达到后，它将被用来模拟在LAM的非线性热处理过程中的沉淀，从而使需要调整的工艺参数的理解，以优化固有的热处理。模拟结果将与原子探针层析成像结果进行比较。此外，化学和热的不均匀性发生在LAM的沉淀动力学的影响将进行研究。