Elucidating the Impact of Processing Parameters of Additive Manufactured Materials Using Microscale Tensile Samples

2020 ◽  
pp. 313-333
Author(s):  
Michael Duffy ◽  
Salahudin Nimer ◽  
Marc Zupan ◽  
Steven Storck
Keyword(s):  
Processing Parameters ◽  
The Impact

scholarly journals Mechanical Behavior of Hydroxyapatite-Chitosan Composite: Effect of Processing Parameters

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Hamid Ait Said ◽  
Hassan Noukrati ◽  
Hicham Ben Youcef ◽  
Ayoub Bayoussef ◽  
Hassane Oudadesse ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Compressive Strength ◽  
Mechanical Strength ◽  
Bone Repair ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Processing Parameters ◽  
Composite Effect ◽  
Solid Liquid ◽  
The Impact

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites were formulated via solid-liquid technic and freeze-drying. The prepared composites had an apatitic nature, which was demonstrated by X-ray diffraction and Infrared spectroscopy analyses. The impact of the solid/liquid (S/L) ratio and the content and the molecular weight of the polymer on the composite mechanical strength was investigated. An increase in the S/L ratio from 0.5 to 1 resulted in an increase in the compressive strength for HA-CSL (CS low molecular weight: CSL) from 0.08 ± 0.02 to 1.95 ± 0.39 MPa and from 0.3 ± 0.06 to 2.40 ± 0.51 MPa for the HA-CSM (CS medium molecular weight: CSM). Moreover, the increase in the amount (1 to 5 wt%) and the molecular weight of the polymer increased the mechanical strength of the composite. The highest compressive strength value (up to 2.40 ± 0.51 MPa) was obtained for HA-CSM (5 wt% of CS) formulated at an S/L of 1. The dissolution tests of the HA-CS composites confirmed their cohesion and mechanical stability in an aqueous solution. Both polymer and apatite are assumed to work together, giving the synergism needed to make effective cylindrical composites, and could serve as a promising candidate for bone repair in the orthopedic field.

scholarly journals Characteristics of Cr-B Coatings Produced on Vanadis® 6 Tool Steel Using Laser Processing

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2621
Author(s):  
Aneta Bartkowska
Keyword(s):  
Corrosion Resistance ◽  
Tool Steel ◽  
Laser Processing ◽  
Chemical Elements ◽  
Steel Substrate ◽  
Processing Parameters ◽  
Beam Power ◽  
Laser Beam Power ◽  
High Microhardness ◽  
The Impact

The paper presents the results of a study of the microstructure, chemical composition, microhardness and corrosion resistance of Cr-B coatings produced on Vanadis 6 tool steel. In this study, chromium and boron were added to the steel surface using a laser alloying process. The main purpose of the study was to determine the impact of those chemical elements on surface properties. Chromium and boron as well as their mixtures were prepared in various proportions and then were applied on steel substrate in the form of precoat of 100 µm thickness. Depending on the type of precoat used and laser processing parameters, changes in microstructure and properties were observed. Coatings produced using precoat containing chromium and boron mixture were characterized by high microhardness (900 HV0.05–1300 HV0.005) while maintaining good corrosion resistance. It was also found that too low laser beam power contributed to the formation of cracks and porosity.

The Study of Quality Monitoring and Control for Laser Cutting Based on Pulse-Induced Acoustic Sound

2012 ◽  
Vol 182-183 ◽  
pp. 422-426 ◽  
Author(s):  
Hui Juan Hao ◽  
Guang He Cheng ◽  
Ji Yong Xu
Keyword(s):  
Adaptive Control ◽  
Laser Cutting ◽  
Cutting Speed ◽  
Processing Parameters ◽  
Wavelet Denoising ◽  
Quality Monitoring ◽  
Monitoring And Control ◽  
Time Frequency ◽  
And Control ◽  
The Impact

In this paper, the pulse-induced acoustic sound in laser cutting is collected, and the data processing is performed with wavelet denoising and time-frequncy analyzing. The impact of laser processing parameters on the acoustic signal is discussed; and further analysis of the effect of cutting speed is conducted. The corresponding relationship between the best velocity and the maximum time-frequency energy density is got; also the plan of adaptive control in laser cutting is designed. The results in this paper can provide important parameters for adaptive control of laser cutting.

scholarly journals Indoor air quality improvement and purification by atmospheric pressure Non-Thermal Plasma (NTP)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Prince Junior Asilevi ◽  
Patrick Boakye ◽  
Sampson Oduro-Kwarteng ◽  
Bernard Fei-Baffoe ◽  
Yen Adams Sokama-Neuyam
Keyword(s):  
Air Quality ◽  
Built Environment ◽  
Indoor Air Quality ◽  
Removal Efficiency ◽  
Indoor Air ◽  
Thermal Plasma ◽  
Processing Parameters ◽  
Optimum Conditions ◽  
Non Thermal Plasma ◽  
The Impact

AbstractNon-thermal plasma (NTP) is a promising technology for the improvement of indoor air quality (IAQ) by removing volatile organic compounds (VOCs) through advanced oxidation process (AOP). In this paper, authors developed a laboratory scale dielectric barrier discharge (DBD) reactor which generates atmospheric NTP to study the removal of low-concentration formaldehyde (HCHO), a typical indoor air VOC in the built environment associated with cancer and leukemia, under different processing conditions. Strong ionization NTP was generated between the DBD electrodes by a pulse power zero-voltage switching flyback transformer (ZVS-FBT), which caused ionization of air molecules leading to active species formation to convert HCHO into carbon dioxide (CO2) and water vapor (H2O). The impact of key electrical and physical processing parameters i.e. discharge power (P), initial concentration (Cin), flow rate (F), and relative humidity (RH) which affect the formaldehyde removal efficiency (ɳ) were studied to determine optimum conditions. Results show that, the correlation coefficient (R2) of removal efficiency dependence on the processing parameters follow the order R2 (F) = 0.99 > R2 (RH) = 0.96, > R2 (Cin) = 0.94 > R2 (P) = 0.93. The removal efficiency reached 99% under the optimum conditions of P = 0.6 W, Cin = 0.1 ppm, F = 0.2 m3/h, and RH = 65% with no secondary pollution. The study provided a theoretical and experimental basis for the application of DBD plasma for air purification in the built environment.

scholarly journals Considering different recent advancements in GNSS on real-time zenith troposphere estimates

GPS Solutions ◽  
2020 ◽  
Vol 24 (4) ◽  
Author(s):  
Tomasz Hadas ◽  
Thomas Hobiger ◽  
Pawel Hordyniec
Keyword(s):  
Real Time ◽  
Weighting Function ◽  
Functional Model ◽  
Processing Parameters ◽  
Gradient Estimation ◽  
International Gnss Service ◽  
Total Delay ◽  
Time Service ◽  
Gnss Meteorology ◽  
The Impact

Abstract Global navigation satellite system (GNSS) remote sensing of the troposphere, called GNSS meteorology, is already a well-established tool in post-processing applications. Real-time GNSS meteorology has been possible since 2013, when the International GNSS Service (IGS) established its real-time service. The reported accuracy of the real-time zenith total delay (ZTD) has not improved significantly over time and usually remains at the level of 5–18 mm, depending on the station and test period studied. Millimeter-level improvements are noticed due to GPS ambiguity resolution, gradient estimation, or multi-GNSS processing. However, neither are these achievements combined in a single processing strategy, nor is the impact of other processing parameters on ZTD accuracy analyzed. Therefore, we discuss these shortcomings in detail and present a comprehensive analysis of the sensitivity of real-time ZTD on processing parameters. First, we identify a so-called common strategy, which combines processing parameters that are identified to be the most popular among published papers on the topic. We question the popular elevation-dependent weighting function and introduce an alternative one. We investigate the impact of selected processing parameters, i.e., PPP functional model, GNSS selection and combination, inter-system weighting, elevation-dependent weighting function, and gradient estimation. We define an advanced strategy dedicated to real-time GNSS meteorology, which is superior to the common one. The a posteriori error of estimated ZTD is reduced by 41%. The accuracy of ZTD estimates with the proposed strategy is improved by 17% with respect to the IGS final products and varies over stations from 5.4 to 10.1 mm. Finally, we confirm the latitude dependency of ZTD accuracy, but also detect its seasonality.

Mechanical and Processing Characterisation of Effective Behaviour of Wood-Plastic Composites by Analytical and Numerical Simulation

2008 ◽  
Vol 575-578 ◽  
pp. 959-971
Author(s):  
Aleš Hančič ◽  
Karl Kuzman ◽  
Franc Kosel ◽  
Andrej Glojek ◽  
António M. Cunha ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Processing Parameters ◽  
Design Guidelines ◽  
Natural Fibres ◽  
Past Century ◽  
Plastic Composite ◽  
Average Fibre ◽  
Mould Cavity ◽  
Mould Design ◽  
The Impact

The development of a new composite that is compounded of natural fibres and of a low price polymer, such as HDPE or PP, began in the last decade of the past century. While this is a rather new material no attempts have been made to analytically describe and simulate mechanical properties of this material. There is also a great lack of knowledge in describing fine tuned processing parameters. Therefore, in the first part of this article micromechanical approach based upon Generalised Method of Cells (GMC) is introduced to simulate properties of injection moulded wood-plastic composite compounded of polypropylene (PP) or polystyrene (PS) and of wood or cellulose short fibres. Materials have first been scanned with an optical and electron microscope to determine average fibre properties and their scatter. These values are then used to determine elastic and plastic response of the composite alongside with its tensile strength and maximum elongation, where the Tsai-Hill failure criterion has been used. The results of the simulation are then compared to experimental data in order to evaluate practical usage of this method. The second part of the article is focused on the simulation of injection moulding where test specimens were injected and the search for optimum injection parameters was performed. Various mechanical and rheological tests were performed and in addition practical industrial products were injected to observe the impact of various natural fibres on the filling of the mould cavity. Every experiment and process was then compared to the numerical simulation in order to evaluate applicability of numerical simulations under real conditions. On the basis of these experiments detailed mould design guidelines are given.

scholarly journals MATERIAL AND THERMAL ANALYSIS OF LASER SINTERTED PRODUCTS

2013 ◽  
Vol 7 (1) ◽  
pp. 15-19 ◽  
Author(s):  
Radovan Hudák ◽  
Martin Šarik ◽  
Róbert Dadej ◽  
Jozef Živčák ◽  
Daniela Harachová
Keyword(s):  
Thermal Analysis ◽  
Heat Stress ◽  
Thermal Stresses ◽  
Processing Parameters ◽  
Sintering Process ◽  
Input Processing ◽  
Thermal Simulations ◽  
The Impact ◽  
Selection Of

Abstract Thermal analysis of laser processes can be used to predict thermal stresses and consequently deformation in a completed part. Analysis of temperature is also the basic for feedback of laser processing parameters in manufacturing. The quality of laser sintered parts greatly depends on proper selection of the input processing parameters, material properties and support creation. In order to relatively big heat stress in the built part during sintering process, the thermal simulation and thermal analysis, which could help better understand and solve the issue of parts deformations is very important. Main aim of presented work is to prepare input parameters for thermal simulations by the use of RadTherm software (Thermoanalytics Inc., USA), directly during the sintering process and after the process and find out the impact of the heat stress on a final shape and size of the prototype. Subsequently, an annealing process of constructed products after DMLS could be simulated and specified.

scholarly journals Three-Dimensional Printed PLA and PLA/PHA Dumbbell-Shaped Specimens: Material Defects and Their Impact on Degradation Behavior

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2005 ◽  
Author(s):  
Joanna Rydz ◽  
Jakub Włodarczyk ◽  
Jennifer Gonzalez Ausejo ◽  
Marta Musioł ◽  
Wanda Sikorska ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Hydrolytic Degradation ◽  
Processing Parameters ◽  
Polymer Materials ◽  
Original Research ◽  
Polymer Properties ◽  
Subsequent Behavior ◽  
And Behavior ◽  
The Impact ◽  
Printing Direction

The use of (bio)degradable polymers, especially in medical applications, requires a proper understanding of their properties and behavior in various environments. Structural elements made of such polymers may be exposed to changing environmental conditions, which may cause defects. That is why it is so important to determine the effect of processing conditions on polymer properties and also their subsequent behavior during degradation. This paper presents original research on a specimen’s damage during 70 days of hydrolytic degradation. During a standard hydrolytic degradation study of polylactide and polylactide/polyhydroxyalkanoate dumbbell-shaped specimens obtained by 3D printing with two different processing build directions, exhibited unexpected shrinkage phenomena in the last degradation series, representing approximately 50% of the length of the specimens irrespective of the printing direction. Therefore, the continuation of previous ex-ante research of advanced polymer materials is presented to identify any possible defects before they arise and to minimize the potential failures of novel polymer products during their use and also during degradation. Studies on the impact of a specific processing method, i.e., processing parameters and conditions, on the properties expressed in molar mass and thermal properties changes of specimens obtained by three-dimensional printing from polyester-based filaments, and in particular on the occurrence of unexpected shrinkage phenomena after post-processing heat treatment, are presented.

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