scholarly journals Linear elastic finite element investigation of titanium specimen produced by Additive Manufacturing

2019 ◽  
Vol 4 (4) ◽  
pp. 85-91
Author(s):  
Dániel Szabó
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Additive Manufacturing ◽  
Solid Material ◽  
Material Structure ◽  
Linear Elastic ◽  
On Demand ◽  
Unit Cells ◽  
Metal Additive ◽  
Titanium Specimen

Nowadays orthopaedic implants are mainly fabricated from solid material (titanium alloy). The mechanical properties of these implants are much stronger than human bone tissue’s properties, and this leads to fixation problems and a short lifetime, but today these problems can be eliminated with the usage of metal additive manufacturing. The mechanical properties of the implants can be influenced on demand with the variation of the material structure using different sizes and types of unit cells for building up its structure.

scholarly journals Effect of Interlayer Cooling on the Preparation of Ni-Based Coatings on Ductile Iron

Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 544
Author(s):  
Yuyu He ◽  
Yijian Liu ◽  
Jiquan Yang ◽  
Fei Xie ◽  
Wuyun Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Additive Manufacturing ◽  
Dilution Rate ◽  
Process Parameters ◽  
Ductile Iron ◽  
Storage Effect ◽  
Thickness Increase ◽  
Average Grain Size ◽  
Metal Additive

In metal additive manufacturing without interlayer cooling, the macro-size of the layer itself is difficult to control due to the thermal storage effect. The effect of interlayer cooling was studied by cladding Ni-based coatings on the substrate of ductile iron. The results show that under the same process parameters, compared with non-interlayer cooling deposition, the dilution rate is better, and the thickness increase of interlayer cooling deposition is more uniform, which is conducive to controlling the macro-size of the interlayer cooling deposition. Furthermore, interlayer cooling deposition has fewer impurities and more uniform microstructures. Moreover, the average grain size is refined and the dendrite growth is inhibited, which improves the mechanical properties of the coating. Therefore, the hardness of the interlayer cooling specimens is greater than that of the non-interlayer-cooled specimens.

Material-structure-performance integrated laser-metal additive manufacturing

Science ◽  
2021 ◽  
Vol 372 (6545) ◽  
pp. eabg1487
Author(s):  
Dongdong Gu ◽  
Xinyu Shi ◽  
Reinhart Poprawe ◽  
David L. Bourell ◽  
Rossitza Setchi ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
High Performance ◽  
Material Structure ◽  
Metal Additive Manufacturing ◽  
Material Development ◽  
Design And Manufacturing ◽  
And Performance ◽  
The Right ◽  
And Function ◽  
Metal Additive

Laser-metal additive manufacturing capabilities have advanced from single-material printing to multimaterial/multifunctional design and manufacturing. Material-structure-performance integrated additive manufacturing (MSPI-AM) represents a path toward the integral manufacturing of end-use components with innovative structures and multimaterial layouts to meet the increasing demand from industries such as aviation, aerospace, automobile manufacturing, and energy production. We highlight two methodological ideas for MSPI-AM—“the right materials printed in the right positions” and “unique structures printed for unique functions”—to realize major improvements in performance and function. We establish how cross-scale mechanisms to coordinate nano/microscale material development, mesoscale process monitoring, and macroscale structure and performance control can be used proactively to achieve high performance with multifunctionality. MSPI-AM exemplifies the revolution of design and manufacturing strategies for AM and its technological enhancement and sustainable development.

Fracture Mechanisms in High-Cycle Fatigue of Selective Laser Melted Ti-6Al-4V

2014 ◽  
Vol 627 ◽  
pp. 125-128 ◽  
Author(s):  
Marco Simonelli ◽  
Y.Y. Tse ◽  
C. Tuck
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Selective Laser Melting ◽  
High Cycle Fatigue ◽  
Fatigue Performance ◽  
Fracture Mechanisms ◽  
Cycle Fatigue ◽  
Laser Melting ◽  
Manufacturing Technique ◽  
Metal Additive

Selective laser melting (SLM) is an attractive metal additive manufacturing technique that can create functional finished components. The microstructure that originates from SLM, however, differs in many aspects from that obtained from conventional manufacturing. In addition, the microstructure-mechanical properties relationship is not yet fully understood. In this research, the high-cycle fatigue performance of SLM Ti-6Al-4V was studied. The dominant fracture mechanisms were reported and discussed in relation to the microstructure of the specimens.

scholarly journals Mitigating Scatter in Mechanical Properties in AISI 410 Fabricated via Arc-Based Additive Manufacturing Process

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4855 ◽  
Author(s):  
Sougata Roy ◽  
Benjamin Shassere ◽  
Jake Yoder ◽  
Andrzej Nycz ◽  
Mark Noakes ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Large Scale ◽  
Gas Metal Arc Welding ◽  
Martensitic Steels ◽  
Stamping Dies ◽  
Metal Arc Welding ◽  
Δ Ferrite ◽  
Tensile Data ◽  
Metal Additive

Wire-based metal additive manufacturing utilizes the ability of additive manufacturing to fabricate complex geometries with high deposition rates (above 7 kg/h), thus finding applications in the fabrication of large-scale components, such as stamping dies. Traditionally, the workhorse materials for stamping dies have been martensitic steels. However, the complex thermal gyrations induced during additive manufacturing can cause the evolution of an inhomogeneous microstructure, which leads to a significant scatter in the mechanical properties, especially the toughness. Therefore, to understand these phenomena, arc-based additive AISI 410 samples were fabricated using robotic gas metal arc welding (GMAW) and were subjected to a detailed characterization campaign. The results show significant scatter in the tensile properties as well as Charpy V-notch impact toughness data, which was then correlated to the microstructural heterogeneity and delta (δ) ferrite formation. Post-processing (austenitizing and tempering) treatments were developed and an ~70% reduction in the scatter of tensile data and a four-times improvement in the toughness were obtained. The changes in mechanical properties were rationalized based on the microstructure evolution during additive manufacturing. Based on these, an outline to tailor the composition of “printable” steels for tooling with isotropic and uniform mechanical properties is presented and discussed.

scholarly journals The Effect of Laser Remelting on the Microstructure and Mechanical Properties of the Bonding Interface in a Hybrid Metal Additive Manufacturing Process

2021 ◽  
Author(s):  
Fei Xue ◽  
Xin Cui ◽  
Longfei Zheng ◽  
Mian Li ◽  
Xuewei Fang
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Substrate Surface ◽  
Complex Structure ◽  
Bonding Interface ◽  
Machining Process ◽  
Laser Remelting ◽  
Metal Additive Manufacturing ◽  
Wire Arc Additive Manufacturing ◽  
Metal Additive

Abstract In order to realize both high-efficient forming with the wire arc additive manufacturing (WAAM) and precise forming with the laser metal deposition (LMD) for some complex-structure and high-precision parts, a hybrid metal additive manufacturing method is proposed. The part is decomposed into sub volumes, then the sub volumes with relatively simple-structure features are formed through WAAM as a substrate, and the other sub volumes with more complex-structure or small-sized features are formed through LMD on the former substrate. However, the mechanical properties of the bonding interface would be reduced, if the later sub volumes are directly deposited by LMD on the rough WAAM substrate surface. In order to avoid unnecessary machining process between WAAM and LMD for high efficiency, and ensure the mechanical properties of WAAM-LMD bonding interface the laser remelting method is applied for improving the profile of WAAM substrate surface. The simulation model of heat transfer and fluid flow in the laser remelting process is established, the influence of the laser power and the scanning speed on the surface-profile improvement is researched by simulation and verified by experiments, Based on that the remelting process parameters are optimized. Furthermore, based on the WAAM formed substrate, the LMD formed volumes are deposited directly, after surface milling and after laser remelting, respectively. Then the microstructure and the mechanical properties of the bonding interface are compared among the three process methods, the feasibility of the laser remelting method for improving the bonding interface performance is verified.

Investigations for Safe Grinding of Ti-6Al-4V Parts Produced by Direct Metal Laser Sintering (DMLS) Technology

2014 ◽  
Author(s):  
Radu Pavel ◽  
Anil K. Srivastava
Keyword(s):  
Titanium Alloy ◽  
Additive Manufacturing ◽  
Residual Stresses ◽  
Diffraction Method ◽  
Laser Sintering ◽  
Grinding Wheel ◽  
Material Structure ◽  
Direct Metal Laser Sintering ◽  
Machining Processes ◽  
Grinding Conditions

Direct Metal Laser Sintering (DMLS) is an additive manufacturing technology that can construct medium to small size parts very efficiently in comparison to traditional machining processes. The ability of this technology to grow complex parts made of high strength titanium- and nickel-based alloys led to increasing interest from aerospace, defense, and medical industries. Although the technology allows growing parts close to their final shape, the active surfaces still need a finishing operation such as grinding to meet the tight tolerances and surface finish requirements. Due to the novelty of the DMLS technology, and the relatively recent developments of titanium alloy powders, there is a need for testing and validating the capabilities of the components manufactured through a combination of DMLS and grinding processes. This paper presents the findings of an experimental study focused on the effect of various grinding conditions on the surface integrity of titanium alloy (Ti-6Al-4V) specimens produced using DMLS technology. The goal is to identify dressing and grinding conditions that would result in ground surfaces free of defects such as micro-cracks, discoloration of surfaces and/or burn marks due to high heat generated during grinding. The residual stresses were used to quantify the effect of the grinding conditions on the ground surfaces. These investigations were conducted on an instrumented CNC surface grinding machine, using a silicon-carbide grinding wheel and a water-based fluid. The X-ray diffraction method was used to measure the residual stresses. Two batches of specimens were manufactured for these tests. The growing strategy of the specimens and the presence of apparent defects in material structure are considered some of the main causes for the differences observed in the outcomes of the grinding trials. The results of these investigations support the need for continuing research in the additive manufacturing field to develop methods and technologies that will ensure a high level of consistency of the grown parts.

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