scholarly journals Micro-FDM process capability and post-processing effects on mechanical properties

2019 ◽  
Author(s):  
Claudia Pagano ◽  
Vito Basile ◽  
Francesco Modica ◽  
Irene Fassi
Keyword(s):  
Mechanical Properties ◽  
Process Capability ◽  
Post Processing ◽  
Processing Effects

scholarly journals Tailoring Microstructure and Mechanical Properties of Additively-Manufactured Ti6Al4V Using Post Processing

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 658
Author(s):  
Yaron Itay Ganor ◽  
Eitan Tiferet ◽  
Sven C. Vogel ◽  
Donald W. Brown ◽  
Michael Chonin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Fatigue Resistance ◽  
Electron Beam Melting ◽  
High Reliability ◽  
National Laboratory ◽  
Post Processing ◽  
Proof Stress ◽  
Β Phase ◽  
Microstructure And Mechanical Properties

Additively-manufactured Ti-6Al-4V (Ti64) exhibits high strength but in some cases inferior elongation to those of conventionally manufactured materials. Post-processing of additively manufactured Ti64 components is investigated to modify the mechanical properties for specific applications while still utilizing the benefits of the additive manufacturing process. The mechanical properties and fatigue resistance of Ti64 samples made by electron beam melting were tested in the as-built state. Several heat treatments (up to 1000 °C) were performed to study their effect on the microstructure and mechanical properties. Phase content during heating was tested with high reliability by neutron diffraction at Los Alamos National Laboratory. Two different hot isostatic pressings (HIP) cycles were tested, one at low temperature (780 °C), the other is at the standard temperature (920 °C). The results show that lowering the HIP holding temperature retains the fine microstructure (~1% β phase) and the 0.2% proof stress of the as-built samples (1038 MPa), but gives rise to higher elongation (~14%) and better fatigue life. The material subjected to a higher HIP temperature had a coarser microstructure, more residual β phase (~2% difference), displayed slightly lower Vickers hardness (~15 HV10N), 0.2% proof stress (~60 MPa) and ultimate stresses (~40 MPa) than the material HIP’ed at 780 °C, but had superior elongation (~6%) and fatigue resistance. Heat treatment at 1000 °C entirely altered the microstructure (~7% β phase), yield elongation of 13.7% but decrease the 0.2% proof-stress to 927 MPa. The results of the HIP at 780 °C imply it would be beneficial to lower the standard ASTM HIP temperature for Ti6Al4V additively manufactured by electron beam melting.

scholarly journals Post-Processing Techniques to Enhance the Quality of Metallic Parts Produced by Additive Manufacturing

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 77
Author(s):  
Muhammad Arif Mahmood ◽  
Diana Chioibasu ◽  
Asif Ur Rehman ◽  
Sabin Mihai ◽  
Andrei C. Popescu
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Post Processing ◽  
Laser Polishing ◽  
Shock Peening ◽  
Processing Techniques ◽  
Am Processes ◽  
Conventional Machining

Additive manufacturing (AM) processes can produce three-dimensional (3D) near-net-shape parts based on computer-aided design (CAD) models. Compared to traditional manufacturing processes, AM processes can generate parts with intricate geometries, operational flexibility and reduced manufacturing time, thus saving time and money. On the other hand, AM processes face complex issues, including poor surface finish, unwanted microstructure phases, defects, wear tracks, reduced corrosion resistance and reduced fatigue life. These problems prevent AM parts from real-time operational applications. Post-processing techniques, including laser shock peening, laser polishing, conventional machining methods and thermal processes, are usually applied to resolve these issues. These processes have proved their capability to enhance the surface characteristics and physical and mechanical properties. In this study, various post-processing techniques and their implementations have been compiled. The effect of post-processing techniques on additively manufactured parts has been discussed. It was found that laser shock peening (LSP) can cause severe strain rate generation, especially in thinner components. LSP can control the surface regularities and local grain refinement, thus elevating the hardness value. Laser polishing (LP) can reduce surface roughness up to 95% and increase hardness, collectively, compared to the as-built parts. Conventional machining processes enhance surface quality; however, their influence on hardness has not been proved yet. Thermal post-processing techniques are applied to eliminate porosity up to 99.99%, increase corrosion resistance, and finally, the mechanical properties’ elevation. For future perspectives, to prescribe a particular post-processing technique for specific defects, standardization is necessary. This study provides a detailed overview of the post-processing techniques applied to enhance the mechanical and physical properties of AM-ed parts. A particular method can be chosen based on one’s requirements.

Printing of Microscale Nanotwinned Copper Interconnections Using Localized Pulsed Electrodeposition (L-PED)

2018 ◽  
Author(s):  
Ali Behroozfar ◽  
Soheil Daryadel ◽  
S. Reza Morsali ◽  
Rodrigo A. Bernal ◽  
Majid Minary-Jolandan
Keyword(s):  
Mechanical Properties ◽  
Electrical Resistivity ◽  
Additive Manufacturing ◽  
High Resistance ◽  
Environmental Conditions ◽  
Coarse Grained ◽  
Post Processing ◽  
Manufacturing Technique ◽  
Conductive Substrate ◽  
Pulsed Electrodeposition

Nanotwinned (nt) metals exhibit superior electrical and mechanical properties compared to their coarse-grained and nano-grained counterparts. They have a unique microstructure with grains that contain layered nanoscale twins divided by coherent twin boundaries (TBs). Since nanotwinned metals have low electrical resistivity and high resistance to electromigration, they are ideal materials for making nanowires, interconnections and switches. In this paper we show the possibility of making nanotwinned copper interconnections on a non-conductive substrate using a novel additive manufacturing technique called L-PED. Through this approach, microscale interconnections can be directly printed on the substrate in environmental conditions and without post processing.

Process Capability of Aerosol-Jet Additive Processes for Long-Runs Up to 10-Hours

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Pradeep Lall ◽  
Amrit Abrol ◽  
Nakul Kothari ◽  
Benjamin Leever ◽  
Scott Miller
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Process Capability ◽  
High Volume ◽  
Process Efficiency ◽  
Shear Load ◽  
Additive Processes ◽  
Sintering Time ◽  
Load To Failure ◽  
Aerosol Jet Printing

Abstract Traditionally, printed circuit assemblies have been fabricated through a combination of imaging and plating-based subtractive processes involving the use of photo-exposure followed by baths for plating and etching in order to form the necessary circuitry on rigid and flexible laminates. The emergence of a number of additive technologies presents an opportunity for the development of processes for manufacturing of flexible substrates by utilizing mainstream additive processes. Aerosol-jet printing is capable of printing lines and spaces below 10 μm in width. The aerosol-jet system also supports a wide variety of materials, including nanoparticle inks, screen-printing pastes, conductive polymers, insulators, adhesives, and biological matter. The adoption of additive manufacturing for high-volume commercial fabrication requires an understanding of the print consistency and electrical mechanical properties. Little literature that addresses the effect of varying sintering time and temperature on the shear strength and resistivity of the printed lines exists. In this study, the effect of process parameters on the resultant line consistency and mechanical and electrical properties has been studied. Print process parameters studied include sheath rate, mass flow rate, nozzle size, substrate temperature, and chiller temperature. Properties include resistance and shear load to failure of the printed electrical line as a function of varying sintering time and temperature. The aerosol-jet machine has been used to print interconnects. Printed samples have been exposed to different sintering times and temperatures. The resistance and shear load to failure of the printed lines have been measured. The underlying physics of the resultant trend was then investigated using elemental analysis and scanning electron microscopy. The effect of line consistency drift over prolonged runtimes has been measured for up to 10 h of runtime. The printing process efficiency has been gaged as a function of the process capability index (Cpk) and process capability ratio (Cp). Printed samples were studied offline utilizing optical profilometry in order to analyze the consistency within the line width, height, and resistance, and shear load to study the variance in electrical and mechanical properties over time.

scholarly journals A Novel Microwave Treatment to Augment the Mechanical Properties of Polymeric Materials

2020 ◽  
Vol 2 (2) ◽  
pp. 14
Keyword(s):  
Mechanical Properties ◽  
Treatment Time ◽  
Polymeric Materials ◽  
Acrylonitrile Butadiene Styrene ◽  
Cost Effective ◽  
Microwave Treatment ◽  
Similar Response ◽  
Post Processing ◽  
Time Saving ◽  
Engineering Polymers

The present study portrays a novel post-processing treatment by using microwave radiations for enhancing the mechanical properties of five commonly used engineering polymers, Poly-amide (PA), Poly-butylene-terephthalate (PBT), Poly-propylene (PP), Poly-carbonate (PC), Acrylonitrile-butadiene-styrene (ABS). The analysis revealed that the crystal structures of the polymers improved after the treatment due to a more favorable rearrangement of crystalline segments within the polymers. Furthermore, tensile properties and tribological performance of microwave treated polymers were found to be significantly better when compared to those of untreated counterparts. The tensile strength, elongation, and wear performance of PA increased by 51%, 286%, and 45%, respectively, only after a treatment of 20 seconds. A similar response was also exhibited by other polymers as well. It was noted that the optimum time for microwave treatment could vary depending on the different crystalline nature of the polymers. The degree of randomness in the molecular chains of semi-crystalline polymers is less; thus, it requires less treatment time. However, for amorphous polymers, as randomness increases, more time is needed. As such, post-processing microwave treatment of polymers has proven beneficial as a cost-effective, time-saving, and environment-friendly technique for enhancing material properties significantly.

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