Tensile properties of aluminium 4047A built in droplet-based metal printing
Tensile properties of aluminium 4047A built in droplet-based metal printing
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DOI：
10.1108/rpj-02-2018-0039
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发表时间：
2019-03-04
影响因子：
3.9
通讯作者：
Volk, Wolfram
中科院分区：
文献类型：
--
作者：
Himmel, Benjamin;Rumschoettel, Dominik;Volk, Wolfram
目的在构建平台上直接打印熔融金属液滴以创建完全致密的金属部件是一种很有前途的增材制造工艺。本研究旨在分析热条件对基于液滴的金属印刷中由铝4047 A制成的部件的拉伸性能的影响。设计/方法/方式一个按需滴与气动驱动的打印头是用来喷射液滴在镍片上安装在加热的构建平台。拉伸试样是由连续液滴沉积的长方体块加工而成，并在万能试验机上进行测试。并对该合金的抗拉强度、均匀延伸率和屈服强度进行了评价。从打印的块中取出显微切片，以检查内部孔隙和金属的微观结构。结果随着界面温度的增加，均匀延伸率从0. 5%增加到12%，而屈服强度从130 MPa降低到90 MPa。当界面温度为530 ° C时，极限抗拉强度从130 MPa增加到最大值190 MPa，当界面温度升高时，极限抗拉强度略有福尔斯。这些值与相同合金的常规铸造部件在相同范围内。作者的假设是，机械性能的主要影响是液体液滴对固体材料的润湿，而不是文献中报道的重熔。独创性/价值-据作者所知，这是第一次，铝4047 A建立了基于液滴的增材制造工艺的机械性能公布不同的界面温度。这也是第一次对力学性能的主要影响归因于润湿而不是重熔。
Purpose Directly printing molten metal droplets on a build platform to create full dense metal parts is a promising additive manufacturing process. This study aims of to analyse the effects of the thermal conditions on the resulting tensile properties of parts made from aluminium 4047A built in droplet-based metal printing. Design/methodology/approach A drop-on-demand print head with pneumatic actuation is used to eject droplets on a nickel sheet mounted on the heated build platform. Tensile specimens are machined from cuboid blocks built by successive droplet deposition and tested in a universal testing machine. The ultimate tensile strength, uniform elongation and yield strength are evaluated and presented. Micro-sections are taken from the printed blocks to examine the internal pores and the metal's microstructure. Findings With an increase in the interface temperature the uniform elongation increases from 0.5 to 12%, while the yield strength decreases from 130 to 90 MPa. The ultimate tensile strength increases from 130 MPa to a maximum of 190 MPa at an interface temperature of 530o C and slightly falls for higher interface temperatures. Those values are in the same range as conventionally casted parts of the same alloy. The authors' hypothesis is that the main effect responsible for the mechanical properties is the wetting of solid material by the liquid droplet and not remelting, as has been reported in literature. Originality/value To the best of the authors' knowledge, this is the first time that mechanical properties of aluminium 4047A built by a droplet-based additive manufacturing process are published for different interface temperatures. It is also the first time that the main effect on mechanical properties is attributed to wetting instead of remelting.