Influence of the 3D Printing Process Settings on Tensile Strength of PLA and HT-PLA

Fused Deposition Modelling (FDM) is presently the most common utilized 3D printing technology. Since this printing technology makes the bodies anisotropic, therefore, investigate the process with different settings is worthwhile. Tensile test specimens of two plastics have been carried out to examine the mechanical properties. Polylactic acid (PLA) and High Temperature PLA (HT-PLA) are the used materials for this purpose. A total of seventy-two test pieces of the two used polymers were printed and evaluated. Three parameters were examined in twelve different settings when printing the tensile test specimens. The considered settings are; six raster directions, three build orientations and two filling factors. The differences in stress-strain curves, tensile strength values and elongation at break were compared among the tested samples. The broken specimens after the tensile test are illustrated, which gave insight into how the test pieces printed with different parameters were fractured. The optimum printing setting is represented at crossed 45/−45° raster direction, X orientation and 100 % fill factor, where the highest tensile strength of 59.7 MPa at HT-PLA and the largest elongation of about 3.5 % at PLA were measured

Tribological Behaviour Comparison of ABS Polymer Manufactured Using Turning and 3D Printing

Additive and subtractive manufacturing of Acrylonitrile Butadiene Styrene (ABS) were employed for fabricating samples. The Additive manufacturing was represented through 3D printing, whereas subtractive manufacturing carried out by Turning. Some developments have been applied for enhancing the performance of the 3D printer. Tribological measurements of the turned and 3D printed specimens have been achieved. Studying the difference between static and dynamic friction factors and the examination of wear values were included. A comparison of the tribological behaviour of the turned and 3D printed ABS polymer has been investigated

Simulation of laser drilling of Inconel X-750 and Ti-5Al-2.5Sn sheets using COMSOL

This study aims to investigate the simulation of laser drilling processes on Inconel X-750 and Ti-5Al-2.5Sn sheets. To this end, COMSOL Multiphysics 5.2 software was employed to carry out the virtual experiments. A JK 701 pulsed Nd:YAG laser was used for drilling through the entire depth of Inconel X-750 and Ti-5Al-2.5Sn plates with a thickness of 2 mm and 3 mm, using laser pulses of a millisecond in time. The laser parameters varied in different combinations for well-controlled drilling through the entire thickness of the plates. Effects of laser peak power (10-20 kW) and pulse duration (0.5-2.5 ms) have been determined via studying the temperature distribution on the cross-section of the images taken in the simulation tests. Characterizing the optimum conditions obtained from the combination of parameters that improve the hole quality is an essential objective in this paper. The results suggest that the hole's diameter and depth have increased linearly as the laser beam's peak power and pulse duration are elevated. An improvement in the hole's taper ratio (the best value is 0.72) was observed as the laser beam pulse duration was longer, since an isosceles trapezoid shape was formed instead of a conical. The pulse duration exhibited more impact on the crater depth progression than the peak power. This work's outcomes might be helpful for researchers in terms of the optimum parameters proposed when studying the laser drilling of the mentioned alloys experimentally. The procedure and findings of this study are not presented elsewhere

Accuracy investigation of 3D printed PLA with various process parameters and different colors

The accuracy of three-dimensional (3D) printing is how the dimensions of a measured product are close to its original model's nominal values. Thus, dimensional accuracy is essential for determining the machine's reliability to produce each object according to the expected results. In this study, the influence of 3D printing process parameters on the dimensional accuracy of specimens manufactured using Polylactic acid (PLA) material is investigated. Based on fused deposition modeling (FDM) technology, cylindrical and dog-bone tensile test samples are fabricated at various process parameters, including build orientation, raster direction angle, and layer thickness. PLA filaments with three different colors (white, grey, and black) are utilized to produce the required test pieces. The dimensional accuracy for cylindrical (diameter and length) and dog-bone (width and thickness) samples have been evaluated. The nominal values are considered the reference to determine the accuracy percentage for each specimen. The weight of all test pieces is also examined, and its precision is assessed. The optimum process parameter settings have been defined to minimize the error percentage in the dimensions of the printed parts. According to the results, a high overall dimensional accuracy of 98.81% was achieved, which indicates the ability of commercial FDM 3D printers as an inexpensive and decent quality alternative for producing utilitarian parts. The filament's color displayed a notable impact on the test pieces' weight, where the difference between the heaviest (white) and lightest (black) specimens is almost a percentage of 7.24%. A remarkable influence was noticed for the layer thickness parameter on the accuracy, meanwhile the raster direction angle parameter appeared no effect when the number of layers and the contour size are the same. The data obtained from this study might help identify the optimum configurations that guide the production of components using thermoplastic filaments through FDM 3D printing

Prediction on the wear rate of epoxy composites reinforced micro-filler of the natural material residue using Taguchi – neural network

The abrasive wear rate of epoxy composites reinforced with fillers sourced from recycled natural waste consisting of pollen of palm (PPW) and seashells (SSW) was studied. Due to the importance of polymer composites used in the tribological couplings of machinery structures, as well as their possible use in brake pads as alternative materials for harmful components in environmentally polluted asbestos, the current research seeks to develop the tribological properties of composite materials reinforced with natural fillers and environmentally friendly. The research investigated the effect of two factors, the weight percentage of natural filler wt. % (0.5 %,1 %, and 1.5 %) and testing loads (1000 g, 2000 g, 3000 g) upon the wear resistance of epoxy composites. The importance of developing epoxy compounds is evident, especially since their work does not require lubricating conditions in various industrial fields, and therefore the development of their bonding properties will increase their operational life and achieve economic benefit for the industrial sector and the environment at the same time. The epoxy composites were subjected to abrasive wear tests under dry friction conditions using a pin-on-disc system. Signal-to-noise (S/N) analysis is adopted to study the influence of the two factors, wt. % and test loads, upon the tribological wear resistance of epoxy composites. A predictive model depending on the regression equation was developed to predict the wear resistance of epoxy composites. The results showed an improvement in the wear resistance of the composite material compared to the epoxy sample without filling by about 47 %. The optimum condition for wear resistance of epoxy composites has been achieved with a weight ratio of (1.5 %) and an applied load of 1000 

Tribological Properties of Medical Material (MED610) Used in 3D Printing PJM Technology

The development of modern manufacturing technologies related to the ongoing industrial revolution Industry 4.0, is largely related to the dynamic development of materials chemistry. This means that currently 3D printing technologies allow the production of physical models using newer materials with better properties and application in new industrial sectors. The article presents the results of tribological tests of the bio-medical material under the trade name MED610, which shows biocompatibility for medical and dental purposes. The paper presents the results of measurements of tribological models of samples designed and manufactured in the shape of rings. Using the variable friction parameters, the wear process was described in the pressure-rotational speed (P-V) system. Moreover, the friction coefficient and wear measured by using the linear method were analyzed. The paper also presents a metrological analysis carried out with the application of an optical profilometer on the surface of the samples after pressing at the contact point of the surface during the test. The preliminary review of the test results showed that the MED610 material exhibited relatively good abrasion resistance. However, it cannot be employed for heavily loaded friction nodes, and in the PV diagram even at a relatively small value, the sample models were destroyed

The effect of adding natural materials waste on the mechanical properties and water absorption of epoxy composite using grey relations analysis

Recently, there has been a tendency for scientific studies to deal with natural materials as fillers and reinforcement for polymer composites, which are used in many different applications due to their environmentally friendly properties when compared to synthetic materials. The current study aims to preserve the environment by dealing with natural materials and their influence on the mechanical properties and water absorption property of the polymer composites. In this study, epoxy composites were produced from local natural sourced non-hazardous raw natural materials using grey relational analysis (GRG). The materials used for fabrication include micro-filler of pollen palm 50 μm, seashell 75 μm and epoxy resin. Nine different composites were prepared using pollen palm and seashell as reinforcement material by varying the wt % of the micro-filler. Rule of the mixture was used for formulation and wt % of (0.5, 1 and 1.5) % reinforcement and 99.5, 99 and 98.5 % epoxy (binder) were used for composites. Grey relational analysis was conducted in order to scale the multi-response performance to a single response. The results indicate that optimum performance can be achieved with the addition of 1.5 wt % micro-filler of seashell, which achieved the first rank, while the second rank achieved by 0.5 wt % micro-filler of palm pollen and seashell when compared to other composites. The addition of micro-fillers has improved greatly the mechanical properties of epoxy composites. The loading of micro-fillers has influenced the water absorption property of composites based epoxy in ascending orde

3D-Printed Spherical-Roof Contoured-Core (SRCC) composite sandwich structures for aerospace applications

This paper studies the compressive properties of the 3D printed spherical-roof contoured-core (SRCC) sandwich panels under quasi-static loading. The novel core structure was used photosensitive resin as a thermoset polymer, which was fabricated through the stereolithography (SLA) process. This paper was focused on investigating the novel SRCC sandwich panels with spherical-roof contoured-core and its diamond-shaped notch core design. The effects of core wall thickness, core design, and boundary condition on the 3D printed sandwich panel were carried out under axial quasi-static loading tests. The results were highlighted that the compressive performance of the 3D printed sandwich panels increased rapidly with increasing the core wall thickness. The core structure was bonded with two skins that provided higher compressive modulus, compressive strength, Fpeak, energy absorption (EA), and specific energy absorption (SEA). Moreover, the failure behaviour of these 3D printed novel composite sandwich panels was also studied

Effect of infill pattern of polylactide acid (PLA) 3D-printed integral sandwich panels under ballistic impact loading

This paper investigates the effect of the infill pattern of polylactide acid (PLA) 3D-printed sandwich panels under ballistic impact loading. Fused deposition modeling (FDM) technique is used to manufacture the PLA 3D-printed integral sandwich panels with four infill patterns: cubic, grid, gyroid, and honeycomb. The ballistic data acquisition system is collected the experimental results with three impact velocities: 109.65, 173.97, and 209.48 m/s. It was revealed that the 3D-printed sandwich panel with cubic infill pattern reached the highest maximum impact load than the other three infill patterns. Moreover, it was highlighted that the sandwich panel with cubic and gyroid infill patterns absorbed 1.41 and 1.15 J and provided better impact resistance characteristics. It is highlighted that the infill pattern plays a vital role in the impact resistance of 3D-printed sandwich structures. Furthermore, it is recommended the three-dimensional (3D) infill pattern, e.g., cubic, gyroid, 3D honeycomb, can provide better impact performance than the two-dimensional (2D) infill pattern

Calculation of Kinetic Parameters of the Thermal Decomposition of Residual Waste of Coniferous Species: Cedrus Deodara

This paper deals with pyrolysis decomposition of Cedrus deodara leaves with the help of thermogravimetric analysis (TGA). Experiments are performed in the presence of inert atmosphere of nitrogen. Experiments are conducted at three different heating rates of 5 °C∙min-1, 10 °C∙min-1 and 15 °C∙min-1 within temperature range of 35 °C to 700 °C. Arrhenius parameters such as activation energy and frequency factor are estimated by Flynn Wall and Ozawa (FWO), Kissinger-Akahira-Sonuse (KAS) and Kissinger. The activation energy and frequency factor calculated by using Kissinger method are 67.63 kJ∙mol-1 and 15.06 . 104 min-1 respectively; whereas the averaged values of the same parameters through FWO and KAS methods are 89.59 kJ∙mol-1 and 84.748 kJ∙mol-1, 17.27 . 108 min-1 and 62.13 . 107 min-1 respectively. Results obtained through Kissinger method represent the actual values of kinetic parameters. Conversely, FWO and KAS methods reflect the apparent values of kinetic parameters, as they are highly influenced by the overlapping of competitive reactions occur during pyrolysis