Processing a glass-forming Zr-based alloy by selective laser melting
Processing a glass-forming Zr-based alloy by selective laser melting
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DOI：
10.1016/j.matdes.2017.08.070
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发表时间：
2017-12-05
影响因子：
8.4
通讯作者：
Kuehn, U.
中科院分区：
文献类型：
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作者：
Pauly, S.;Schricker, C.;Kuehn, U.
采用选择性激光熔化（SLM）法制备了Zr52.5Cu17.9Ni14.6Al10Ti5非晶化粉末。在临界能量密度E-crit = 15 J/mm(3)以下，获得了完全玻璃化的样品。当能量密度较高时，经氧稳定的亚稳大立方相在其他晶相旁边析出。我们引入密度等高线图来确定工艺窗口，从而可以获得相对密度高达98.5%的全玻璃样。系统参数的变化说明了激光功率对获得致密SLM零件的重要性。此外，该合金的孔隙分布对扫描策略相当敏感。SLM样品的抗压强度与铸态玻璃的测量值相当，甚至发现了明显的塑性应变。最后，制作了支架，高能x射线衍射证明它们是完全玻璃化的，而不考虑局部冷却速率的差异。我们的实验有助于更好地理解Zr52.5Cu17.9Ni14.6Al10Ti5在SLM过程中的行为，并有助于使玻璃成形合金越来越容易用于基于激光的增材制造，以克服大块金属玻璃固有的尺寸限制。(C) 2017 Elsevier Ltd.版权所有。
Compact specimens were produced by selective laser melting (SLM) from glass-forming Zr52.5Cu17.9Ni14.6Al10Ti5 powder. Below a critical energy density of E-crit = 15 J/mm(3) fully glassy samples were obtained. When the energy density is higher, the metastable big cube phase, stabilized by oxygen, precipitates next to other crystalline phases. We introduce density contour maps to identify the process window, which allows obtaining fully glassy samples with a high relative density of up to 98.5%. The systematic parameter variation illustrates the importance of laser power for obtaining dense SLM parts. Moreover, the distribution of pores in the present alloy is rather sensitive to the scanning strategy. The compressive strength of the SLM samples is comparable to values measured for as-cast glasses and even a distinct plastic strain is found. Finally, scaffolds were produced and high-energy X-ray diffraction proves that they are fully glassy irrespective of differences in the local cooling rates. Our experiments contribute to better understanding the behaviour of Zr52.5Cu17.9Ni14.6Al10Ti5 during SLM and for making glass-forming alloys progressively more accessible to laser-based additive manufacturing in order to overcome the intrinsic size limitation of bulk metallic glasses. (C) 2017 Elsevier Ltd. All rights reserved.