Fabrication of multi-functional Ni–Ti alloys by laser powder bed fusion

2021 ◽  
Author(s):  
Jianran Lv ◽  
Hongyao Shen ◽  
Jianzhong Fu
Keyword(s):  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Ti Alloys

Grain Refinement of Fe-X Alloys Fabricated by Laser Powder Bed Fusion

2021 ◽  
Vol 1016 ◽  
pp. 580-586
Author(s):  
Hideaki Ikehata ◽  
Eric Jägle
Keyword(s):  
Grain Refinement ◽  
Lattice Misfit ◽  
Average Diameter ◽  
Ferrite Matrix ◽  
Coarse Grained ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Iron Oxide Particles ◽  
Powder Bed ◽  
Ti Alloys

Grain refinement tendency of pure Fe and Fe-X (X=5~10at%Al, 2~10at%Ti) alloys produced by laser powder bed fusion (LPBF) process was investigated. Pure Fe, Al, and Ti powders were dry mixed and cubic samples were built from the mixtures. The microstructure analysis revealed that (1) the microstructure of pure Fe consisted of equiaxed grains having an average diameter of 1.7 μm with fine iron oxide particles. (2) Fe-5 and 10at%Al alloys showed coarse columnar grains. (3) Fe-2at%Ti shows a mixture of fine equiaxed and columnar shape grains. (4) the microstructures of Fe-5at%Ti and 10at%Ti alloys are fully equiaxed, and grain refinement tendency was confirmed with increasing Ti content. Ti(N,O) oxi-nitrides are efficient in reducing the grain size because of the low lattice misfit with the ferrite matrix. Additionally, the effectiveness of Ti(N,O) particles as grain refiners was confirmed by building samples using TiN powder mixed with Fe-10at%Al and Fe-2at%Ti. While these alloys alone are coarse grained, a dispersion of Ti(N,O) particles achieved a fine-grained microstructure.

Fabrication of Integrated Ni-Ti Alloys Possessing Both Super-elastic and Shape Memory Properties by Laser Powder Bed Fusion

2021 ◽  
Author(s):  
Jianran Lv ◽  
Hongyao Shen ◽  
Jianzhong Fu
Keyword(s):  
Shape Memory ◽  
Metallographic Analysis ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Scanning Calorimetry ◽  
Powder Bed ◽  
X Ray ◽  
High Relative Density ◽  
Ti Alloys ◽  
Shape Memory Effects

Abstract Purpose: Integrated Ni-Ti alloys possessing both super-elastic (SE) properties and shape memory effects (SMEs) greatly increase the flexibility of designing complex systems and have broad application prospects. However, existing research mainly focuses on connecting ready-made SE parts and SME parts though welding. Method: In this paper, laser powder bed fusion (LPBF) was used to fabricate integrated Ni-Ti alloys. First, SE parts with high relative density were fabricated with a Ni-rich powder. Then, different process parameters were used to fabricate the SME parts with a Ti-rich powder based on the SE parts. The integrated component with the best mechanical properties herein was selected. Metallographic analysis, energy dispersive X-ray spectroscopy, differential scanning calorimetry and micro-hardness analyses were carried out for this sample. Findings: The results show that the integrated component possessed both SE and SME properties at room temperature. Moreover, at the junction of the two materials, the grains were continuous and complete, which indicates that the joint had good quality. Originality: Our work confirms that LPBF is a feasible method to fabricate integrated Ni-Ti alloys possessing both SE and SME properties.

scholarly journals On the Relevance of Volumetric Energy Density in the Investigation of Inconel 718 Laser Powder Bed Fusion

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 538 ◽  
Author(s):  
Fabrizia Caiazzo ◽  
Vittorio Alfieri ◽  
Giuseppe Casalino
Keyword(s):  
Surface Roughness ◽  
Energy Density ◽  
Process Parameters ◽  
Vickers Hardness ◽  
Powder Bed Fusion ◽  
Processing Conditions ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Fractional Density ◽  
Experimental Variation

Laser powder bed fusion (LPBF) can fabricate products with tailored mechanical and surface properties. In fact, surface texture, roughness, pore size, the resulting fractional density, and microhardness highly depend on the processing conditions, which are very difficult to deal with. Therefore, this paper aims at investigating the relevance of the volumetric energy density (VED) that is a concise index of some governing factors with a potential operational use. This paper proves the fact that the observed experimental variation in the surface roughness, number and size of pores, the fractional density, and Vickers hardness can be explained in terms of VED that can help the investigator in dealing with several process parameters at once.

Heat source model calibration for thermal analysis of laser powder-bed fusion

2020 ◽  
Vol 106 (7-8) ◽  
pp. 3367-3379 ◽  
Author(s):  
Shahriar Imani Shahabad ◽  
Zhidong Zhang ◽  
Ali Keshavarzkermani ◽  
Usman Ali ◽  
Yahya Mahmoodkhani ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Heat Source ◽  
Model Calibration ◽  
Source Model ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Heat Source Model ◽  
Powder Bed

scholarly journals The Effect of Cu Content and Surface Finish on the Metal Dusting Resistance of Additively Manufactured NiCu Alloys

2021 ◽  
Author(s):  
Katrin Jahns ◽  
Anke S. Ulrich ◽  
Clara Schlereth ◽  
Lukas Reiff ◽  
Ulrich Krupp ◽  
...  
Keyword(s):  
Surface Finish ◽  
Powder Bed Fusion ◽  
Metal Dusting ◽  
Laser Powder Bed Fusion ◽  
Roughness Measurement ◽  
Powder Bed ◽  
Cu Content ◽  
Binary Model ◽  
Interesting Candidate ◽  
Nicu Alloys

AbstractDue to the inhibiting behavior of Cu, NiCu alloys represent an interesting candidate in carburizing atmospheres. However, manufacturing by conventional casting is limited. It is important to know whether the corrosion behavior of conventionally and additively manufactured parts differ. Samples of binary NiCu alloys and Monel Alloy 400 were generated by laser powder bed fusion (LPBF) and exposed to a carburizing atmosphere (20 vol% CO–20% H2–1% H2O–8% CO2–51% Ar) at 620 °C and 18 bar for 960 h. Powders and printed samples were investigated using several analytic techniques such as EPMA, SEM, and roughness measurement. Grinding of the material after building (P1200 grit surface finish) generally reduced the metal dusting attack. Comparing the different compositions, a much lower attack was found in the case of the binary model alloys, whereas the technical Monel Alloy 400 showed a four orders of magnitude higher mass loss during exposure despite its Cu content of more than 30 wt%.

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