Effect of build geometry on the β-grain structure and texture in additive manufacture of Ti6Al4V by selective electron beam melting
TL;DR: In this paper, the effect of geometry on the variability in the grain structure and texture, seen in Tisingle bond6Al single bond4V alloy components produced by Selective Electron Beam Melting (SEBM), has been investigated.
About: This article is published in Materials Characterization.The article was published on 2013-10-01 and is currently open access. It has received 570 citations till now. The article focuses on the topics: Texture (crystalline) & Electron backscatter diffraction.
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TL;DR: A review of the emerging research on additive manufacturing of metallic materials is provided in this article, which provides a comprehensive overview of the physical processes and the underlying science of metallurgical structure and properties of the deposited parts.
4,192 citations
TL;DR: In this paper, the authors describe the complex relationship between additive manufacturing processes, microstructure and resulting properties for metals, and typical microstructures for additively manufactured steel, aluminium and titanium are presented.
2,837 citations
Cites background from "Effect of build geometry on the β-g..."
...LBM of Ti-6Al4V [25] and Ta [113], EBM [36] and LMD [2] (both Ti-6Al-4V), yielding grain sizes in build direction that exceed layer thickness....
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...Afterwards, as the build temperature is in the same range as the martensite start temperature Ms, the b-phase may transform diffusionless to a0 if below Ms and then decompose to a, or transform diffusional into a if above Ms [36]....
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...The bulk material generated by in-fill hatching showed the highly textured, coarse prior-b-grains directed parallel to the build direction, as described above [36]....
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...Using a high beam current of up to 30mA and a scan speed of about 104mm/s, temperatures of >700 C of the powder material are achieved for Ti-6Al-4V [8,35,36], while for e....
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...The skin contour however showed a complex structure consisting of an outer layer of fine-curved b-grains which nucleated from the surrounding powder bed and then growing inwards following the curvature of the melt pool, and an inner layer of lath shaped grains growing upwards from previously deposited material [36]....
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TL;DR: In this article, a review of additive manufacturing (AM) techniques for producing metal parts are explored, with a focus on the science of metal AM: processing defects, heat transfer, solidification, solid-state precipitation, mechanical properties and post-processing metallurgy.
Abstract: Additive manufacturing (AM), widely known as 3D printing, is a method of manufacturing that forms parts from powder, wire or sheets in a process that proceeds layer by layer. Many techniques (using many different names) have been developed to accomplish this via melting or solid-state joining. In this review, these techniques for producing metal parts are explored, with a focus on the science of metal AM: processing defects, heat transfer, solidification, solid-state precipitation, mechanical properties and post-processing metallurgy. The various metal AM techniques are compared, with analysis of the strengths and limitations of each. Only a few alloys have been developed for commercial production, but recent efforts are presented as a path for the ongoing development of new materials for AM processes.
1,713 citations
Cites background from "Effect of build geometry on the β-g..."
...Work to study the origins of this texture observed the effect of grain nucleation from powder particles.(174) Additionally, this work demonstrated a clear distinction between the fine grained, equiaxed microstructure of the contour region and the highly oriented, bulk melt....
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TL;DR: In this paper, the recent progress on Ti6Al4V fabricated by three mostly developed additive manufacturing techniques-directed energy deposition (DED), selective laser melting (SLM) and electron beam melting (EBM)-is thoroughly investigated and compared.
1,248 citations
TL;DR: In this paper, the state-of-the-art with respect to inspection methodologies compatible with additively manufactured (AM) processes is explored with the intention of identifying new avenues for research and proposing approaches to integration into future generations of AM systems.
1,024 citations
Cites background from "Effect of build geometry on the β-g..."
...concluded that the skin scan (as part of the scan strategy) produces distinctly different grain structures compared to the bulk of the material [37], which can also lead to the formation of the types of material discontinuities discussed above....
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References
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Book•
01 Jan 2009
TL;DR: Gibson et al. as discussed by the authors presented a comprehensive overview of additive manufacturing technologies plus descriptions of support technologies like software systems and post-processing approaches, and provided systematic solutions for process selection and design for AM Additive Manufacturing Technologies: Rapid Prototyping to Direct Digital Manufacturing.
Abstract: Additive Manufacturing Technologies: Rapid Prototyping to Direct Digital Manufacturing deals with various aspects of joining materials to form parts. Additive Manufacturing (AM) is an automated technique for direct conversion of 3D CAD data into physical objects using a variety of approaches. Manufacturers have been using these technologies in order to reduce development cycle times and get their products to the market quicker, more cost effectively, and with added value due to the incorporation of customizable features. Realizing the potential of AM applications, a large number of processes have been developed allowing the use of various materials ranging from plastics to metals for product development. Authors Ian Gibson, David W. Rosen and Brent Stucker explain these issues, as well as: Providing a comprehensive overview of AM technologies plus descriptions of support technologies like software systems and post-processing approaches Discussing the wide variety of new and emerging applications like micro-scale AM, medical applications, direct write electronics and Direct Digital Manufacturing of end-use components Introducing systematic solutions for process selection and design for AM Additive Manufacturing Technologies: Rapid Prototyping to Direct Digital Manufacturing is the perfect book for researchers, students, practicing engineers, entrepreneurs, and manufacturing industry professionals interested in additive manufacturing.
3,087 citations
TL;DR: In this article, the development of the microstructure of the Ti-6Al-4V alloy processed by selective laser melting (SLM) was studied by light optical microscopy.
2,201 citations
TL;DR: In this article, the main problems associated with the machining of titanium as well as tool wear and the mechanisms responsible for tool failure are discussed. But no equivalent development has been made for cutting titanium alloys due primarily to their peculiar characteristics.
1,417 citations
15 Mar 1998-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, a simplified methodology for investigating the effects of cooling rate from elevated temperature on phase transformations observed in α+β titanium alloys is described, which involves adaptation and refinement of a circumferentially insulated and instrumented Jominy end quench bar, time-temperature profiles obtained during cooling at locations along the bar length providing a complete thermal history.
Abstract: A simplified methodology for investigating the effects of cooling rate from elevated temperature on phase transformations observed in α+β titanium alloys is described. It involves adaptation and refinement of a circumferentially insulated and instrumented Jominy end quench bar, time–temperature profiles obtained during cooling at locations along the bar length providing a complete thermal history. The ability of this procedure to examine the phase transformation for α+β titanium alloys has been demonstrated in Ti–6Al–4V where varying cooling rates from 525 to 1.5°C s−1 are shown to result in a series of martensitic, massive and diffusional phase transformations. Cooling rates above 410°C s−1 result in a fully martensitic microstructure, a massive transformation being observed between 410 and 20°C s−1, this transformation being gradually replaced by diffusion controlled Widmanstatten α formation with decreasing cooling rate.
860 citations
TL;DR: The microstructure and mechanical behavior of simple product geometries produced by layered manufacturing using the electron beam melting (EBM) process and the selective laser melting (SLM) process are compared with those characteristic of conventional wrought and cast products of Ti-6Al-4V.
Abstract: The microstructure and mechanical behavior of simple product geometries produced by layered manufacturing using the electron beam melting (EBM) process and the selective laser melting (SLM) process are compared with those characteristic of conventional wrought and cast products of Ti-6Al-4V. Microstructures are characterized utilizing optical metallography (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and included alpha (hcp), beta (bcc) and alpha(') (hcp) martensite phase regimes which give rise to hardness variations ranging from HRC 37 to 57 and tensile strengths ranging from 0.9 to 1.45 GPa. The advantages and disadvantages of layered manufacturing utilizing initial powders in custom building of biomedical components by EBM and SLM in contrast to conventional manufacturing from Ti-6Al-4V wrought bar stock are discussed.
830 citations