Fleißner-Rieger Christian, Pfeifer Tanja, Turk Christoph, Clemens Helmut
Department of Materials Science, Montanuniversität Leoben, Franz-Josef Straße 18, 8700 Leoben, Austria.
Pankl Racing Systems AG, Additive Manufacturing Technologies, Industriestraße Ost 4, 8605 Kapfenberg, Austria.
Materials (Basel). 2022 Jan 28;15(3):1032. doi: 10.3390/ma15031032.
During the last decades, titanium alloys have been of great interest for lightweight applications due to their high strength in combination with a low material density. Current research activities focus on the investigation of near-α titanium alloys produced by laser powder bed fusion (LPBF). These alloys are known for their superior tensile strength and high creep resistance. This study focuses on the optimization of post-process heat treatments and the impact on tensile and creep strength of a LPBF produced Ti6242S alloy. Therefore, a variety of annealing steps were conducted to gain knowledge about the decomposition process of the non-equilibrium as-built microstructure and the arising influence on the mechanical properties. Components made of Ti6242S and produced by LPBF reveal an extraordinarily high ultimate tensile strength of about 1530 MPa at room temperature, but show a low elongation at fracture (A = 4.3%). Based on microstructure-property relationships, this study recommends precise heat treatments on how to improve the desired mechanical properties in terms of strength, ductility as well as creep resistance. Moreover, this study shows a triplex heat treatment, which enhances the elongation at fracture (A) to 16.5%, while the ultimate tensile strength is still at 1100 MPa.
在过去几十年中，钛合金因其高强度与低材料密度的结合而在轻量化应用中备受关注。当前的研究活动集中在对激光粉末床熔融（LPBF）制备的近α钛合金的研究上。这些合金以其优异的拉伸强度和高抗蠕变性而闻名。本研究聚焦于后处理热处理的优化以及对LPBF制备的Ti6242S合金的拉伸和蠕变强度的影响。因此，进行了各种退火步骤，以了解非平衡铸态微观结构的分解过程以及对力学性能产生的影响。由LPBF制备的Ti6242S制成的部件在室温下显示出约1530 MPa的极高极限抗拉强度，但断裂伸长率较低（A = 4.3%）。基于微观结构-性能关系，本研究就如何在强度、延展性以及抗蠕变性方面改善所需的力学性能推荐了精确的热处理方法。此外，本研究展示了一种三重热处理，可将断裂伸长率（A）提高到16.5%，而极限抗拉强度仍为1100 MPa。
