Effects of Chemical and Mechanical Treatments on the Surface Roughness and Aerodynamic Performance of FDM-Fabricated ABS Airfoils

Fused deposition modelling (FDM) is one of the most commonly used additive manufacturing processes because of its environment-friendly nature and cost-effectiveness. However, it suffers badly from low surface quality due to a larger layer resolution. The surface finish of FDM parts can be enhanced by post chemical treatment using various solvents. The chemical treatment reduces the surface roughness by dissolving the external surfaces of 3D-printed samples. Chemical treatment is an easy, fast and economical technique. In the present investigation, the effect of chemical treatment on surface roughness and tensile strength of acrylonitrile butadiene styrene (ABS) parts made using the FDM process is investigated using two chemicals, namely acetone and 1, 2 dichloroethane. The post chemical treatment dramatically improves the surface finish and dimensional accuracy of ABS specimens. But chemical treatment results in the reduction of the tensile strength. Better tensile strength is obtained while using acetone solvent and a better surface finish is obtained using dichloroethane.

Purpose This study aims to investigate the effects of non-traditional processing techniques on the surface quality and thermal characteristics of parts manufactured from acrylonitrile butadiene styrene (ABS) using fused deposition modelling (FDM) additive manufacturing (AM). Acetone vapour treatment is applied to enhance surface polish and minimize material waste. Design/methodology/approach An experimental approach was adopted to investigate the impact of acetone vapour jet drilling on three-dimensional-printed materials. Specimens were fabricated using FDM with polylactic acid and ABS as the primary materials. A custom-built acetone vapour jet system was used to drill holes in the printed samples under controlled temperature, pressure and exposure time. The drilled holes were analysed for dimensional accuracy, surface roughness and material integrity using optical microscopy and scanning electron microscopy. A comparative assessment with conventional mechanical drilling was performed to evaluate the efficacy and limitations of the vapour jet method. The experimental results were statistically analysed to determine the influence of process parameters on hole quality and material deformation. Findings Removal of extra material substantially improves surface smoothness through extremely extended exposure times to acetone vapour. Increasing melting temperatures, enthalpies indicate superior heat resistance along with finer finishes achieved after treatment, according to a study. Originality/value This work advances the area of AM in showing how effectively acetone vapour treatment can enhance the surface quality and thermal characteristics of ABS parts made using FDM. Attention is drawn on how unusual processing techniques are used to solve common problems in traditional post-processing procedures, including material waste and uneven surface finish.

The applications of Additive Manufacturing (AM) technology have a greater functionality and wider range of application beyond an intention of prototyping. AM is the process of joining materials to form objects from Computer-Aided Design (CAD) models via layer upon layer process. One of AM technologies is the Fused Deposition Modelling (FDM), which use an extrusion method to create a part. FDM has been applied in many manufacturing applications includes an end-used parts. However, FDM tends to have bad surface quality due to staircase effect and post treatment is required. This chemical treatment is one of a way to improve the surface roughness of FDM fabricated parts. This method is one of economical and faster method. In order to enhance the surface finish of Acrylonitrile-Butadiene-Styrene (ABS) FDM parts by performing chemical treatment in an acetone solution as acetone has very low toxicity, high diffusion and low cost chemical solution. Therefore, the aim of this research is to investigate the influence of chemical treatment to the FDM used part in terms of surface roughness as well as the strength. In this project, ten specimens of standard ASTM D638 dogbone specimens have been fabricated using MOJO 3D printer. Five specimens from the dogbone were tested for surface roughness and tensile testing while another five were immersed in the chemical solution before the same testing. Based on results, the surface roughness of chemically treated dogbone has dramatically improved, compared to untreated dogbone with 97.2% of improvement. However, in term of strength, the tensile strength of dogbone is reduced 42.58% due to the rearrange of material properties and chemical effects to the joining of the filaments. In conclusion, chemical treatment is an economical and sustainable approach to enhance the surface quality of AM parts.

PurposeParts created with fused deposition modelling (FDM) have poor surface quality and dimensional accuracy, which limits their applicability in a variety of applications. Therefore, post process of FDM parts seems to be essential to tackle these problems. The purpose of this study is to study the influence of lapping parameters (time, weight and angular velocity) on the surface roughness, material removal rate (MRR) and flexural strength of acrylonitrile butadiene styrene (ABS) parts manufactured by FDM were post processed with the aid of lapping operation.Design/methodology/approachAfter printing the specimens, parts were lapped according to the Taguchi design of experiments. The surface roughness of the lapped parts was then evaluated by using laser profilometry, and the results were compared to study how lapping parameters affected surface roughness. A digital microscope was used to examine the surface damage of components that were being lapped. After that, the flexural strength of lapped parts was compared with the untreated part to study the effect of lapping process on the flexural strength. Finally, the influence of lapping parameters was investigated on the thickness change and MRR.FindingsThe results showed that while by increasing lapping time the surface roughness would improve; angular velocity and weight have an optimal value. The results also illustrated that not only the surface roughness of all ABS samples improve significantly but also the antistrophic behaviour of additively manufactured parts is turned to isotropic behaviour without decreasing flexural strength of specimens. MRR is also proportional to these parameters and by rising the value of them, MRR will increase.Originality/valueThe previous techniques of improving surface roughness whether chemical treatment or mechanical treatment had some disadvantages such as reducing mechanical properties, cost, long time of the process and so forth. As a result, finding a new approach such as lapping process to overcome the problems of previous methods seems to be necessary.

Effect of surface treatments on the bond strength of resin-repaired resin matrix CAD-CAM ceramic: A scoping review.

Lightweight, high strength and high energy absorption material are of interest in aerospace, automobile and defence industries. Sandwich structures with lattice core exhibit high specific strength and stiffness when compared to monolithic structures. The development of different additive manufacturing technologies has enabled the fabrication of complex cellular structures of low relative density, to enable energy management in impact and crash scenarios. It is necessary to investigate and enhance the mechanical properties of the lattice structure fabricated by additive manufacturing. In this thesis, quasi-static compression and flexural behaviour of Kagome sandwich structure fabricated by additive manufacturing is investigated. Fused deposition modelling (FDM) is useful to fabricate various parts of unmanned aerial vehicles (UAV). The structural efficiency of the UAV can be improved by using the cellular lattice structures which provides better specific strength and stiff structures. Thus, it is important to investigate the mechanical properties of the cellular structures fabricated by FDM. Initially, the compressive performance of Kagome unit cell structure of acrylonitrile butadiene styrene (ABS) fabricated by FDM is investigated. The influence of part build orientation, strut diameter and surface roughness on the strength and effective moduli is critically explored. The change in the build orientation improved the average peak strength and effective moduli by 23% and 19% respectively due to the change in strut dimensions with different build orientation as well as the anisotropic compressive behaviour of FDM printed parts. The finite element based numerical simulation results of effective stiffness differed from experimental measurements by 10-17% due to imperfections like voids and surface staircases which are imminent in the parts fabricated by FDM. The surface roughness of the printed parts was reduced by chemical surface treatment with 90% by vol. acetone. Five minutes treatment time on the Kagome specimens proved to be optimal based on the measured surface roughness, compressive strength and effective moduli of Kagome structures. Then, the compressive performance of unit Kagome structure was compared with the multi-units Kagome structures. The effect of the increase in the number of layers in the compressive performance in terms of average strength and effective moduli was also investigated. Also, the performance of uniform density and gradient density Kagome structure and their deformation behaviour were explored. It was found that the performance of the unit structure and multi-unit structure were comparable. The initial failure in both cases was similar and was around the joint of struts with the face sheets. The increase in the number of layers increased the effective moduli of the structure whereas the strength was almost the same within the relative density range of samples tested. The graded density Kagome lattice structure was found to have better energy absorption over the uniform density structures by 35%. Another major contribution of the thesis work is in the design modification of the existing Kagome structure to enhance the compressive performance. A vertical strut was introduced in the existing design and called as strut-reinforced Kagome (SRK) structure. The unit SRK and Kagome structure were successfully fabricated through selective laser melting without any additional support structure. The compression properties of SLM printed Ti-6Al-4V SRK was explored with the variation in the aspect ratio. An analytical prediction for effective modulus and peak strength of SRK structure was proposed and compared with numerical simulation and experimental results. The performance of unit SRK was also compared with unit Kagome structure with the same relative density. The analytical solution well predicted the compressive strength within 12% accuracy with the experimental results whereas the effective moduli differed by 12-24%. For the specific case studied, it was observed that the SRK unit structure had better effective modulus (12.87%) and peak strength (13.42%) than Kagome unit structure. The sub-β-transus heat treatment was carried out on SRK and Kagome samples, and they were subjected to compression tests. The peak strength of the structure reduced by 11-15% while the effective moduli of the structures increased by 40-48% after the heat treatment. The failure strain and energy absorption increased by 37-70% and 19-35% respectively with the heat treatment. Finally, the flexural performance of the sandwich beam with Kagome structure as a core was studied through finite element based numerical simulations. The analytical solutions for different failure modes under three-point bending were derived. A failure mode design map was constructed with non-dimensional failure loads expressed in terms of non-dimensional geometrical parameters of face sheet thickness and core height. Four different cases of various geometrical parameters were studied under three-point bending simulations in ABAQUS®, and the peak load, stiffness and failure mode were observed. The failure mode of the samples matched with the one predicted by failure map for core shear mode A and B and local indentation. The peak loads were found to be within 10% of the solution obtained by the analytical solution.

Additive manufacturing (AM) or 3D printing is a fabrication process, usually layer upon layer, of joining materials to make the desired objects directly from a 3D model. 3D printing allows for complex geometries that would be difficult, if not impossible to create using traditional subtractive methods such as milling, grinding, casting, etc. The nature of the additive process also allows the user to avoid or minimize costs that would be incurred if setting up with a traditional subtractive process. With AM there is no need for fixtures, tooling, or multiple processes to complete the part, which allows AM processes to operate with greater flexibility and lower costs. This flexibility allows 3D printing to produce end-use products for many different applications with lower initial investment, maintenance, labor costs and operating costs. Our research specifically focuses on the Fused Deposition Modeling (FDM) process. Fused Deposition Modeling is a process in which the chosen filament is melted, extruded through a nozzle, and then deposited layer by layer as described above. This FDM process is used not only in rapid prototyping as it was initially intended, but also in mass production of finished products as it holds many advantages over the traditional methods. In 3D printing, parts are usually built in discrete layers, and this often results in a certain amount of structural uncertainty in the form of discontinuities, voids, and poor inter-layer bonding. The 3D printed parts are increasingly being used for end-use products that are subject to higher tolerance, quality, uniformity, and surface finish requirements. Hence, to see greater market penetration, the amount of structural uncertainty must be reduced. In our previous research, we successfully investigated the differences in the ultimate strength and fatigue life for 3D printed Acrylonitrile Butadiene Styrene (ABS) components built by various build/layer orientations. Our previous research also successfully highlighted the ultimate strengths and fatigue life, including SN Curves. However, there is a need for further research to improve the surface finish and the tensile strength of the 3D printed ABS components. This research explores the effects of the surface treatment on the tensile strength of the 3D printed ABS components with various layup-orientation. In this study, Acetone Vaper Smoothing (AVS) was used as the surface treatment of the 3D printed ABS components. Our research found that the AVS method reduces stress concentration and structural uncertainty of the 3D printed ABS components to improve the tensile strength. However, these results only occurred after optimizing the acetone vapor exposure and improving the drying methods since acetone can weaken the layer bonding of the ABS and reduced the tensile strength of the 3D printed ABS components in certain situations. This research also provides the optimal conditions of the acetone vapor exposure time and the drying method.

Effects of surface treatments on ABS mechanical properties from fused filament fabrication

PurposeThis paper aims to investigate the effect of post-processing techniques on dimensional accuracy of laser sintering (LS) of Nylon and Alumide®and fused deposition modelling (FDM) of acrylonitrile butadiene styrene (ABS) materials.Design/methodology/approachAdditive manufacturing (AM) of test pieces using LS of Nylon and Alumide®powders, as well as the FDM of ABS materials, were first conducted. Next, post-processing of the test pieces involved tumbling, shot peening, hand finishing, spray painting, CNC machining and chemical treatment. Touch probe scanning of the test pieces was undertaken to assess the dimensional deviation, followed by statistical analysis using Chi-square and Z-tests.FindingsThe deviation ranges of the original built parts with those being subjected to tumbling, shot peening, hand finishing, spray painting, CNC machining or chemical treatment were found to be different. Despite the rounding of sharp corners and the removal of small protrusions, the dimensional accuracy of relatively wide surfaces of Nylon or Alumide®test pieces were not significantly affected by the tumbling or shot peening processes. The immersion of ABS test pieces into an acetone bath produced excellent dimensional accuracy.Research limitations/implicationsOnly Nylon PA2200 and Alumide®processed through LS and ABS P400 processed through FDM were investigated. Future work could also examine other materials and using parts produced with other AM processes.Practical implicationsThe service bureaus that produce prototypes and end-use functional parts through AM will be able to apply the findings of this investigation.Originality/valueThis research has outlined the differences of post-processing techniques such as tumbling, shot peening, hand finishing, spray painting, CNC machining and chemical treatment. The paper discusses the advantages and disadvantages of each of those methods and suggests that the immersion of ABS test pieces into an acetone bath produced excellent dimensional accuracy.

The aim of this ex vivo study was to assess the ability to remove oral biofilm by different combinations of mechanical and chemical treatments on smooth and rough titanium surfaces, as well as their impact on osteoconduction. Forty-eight sandblasted acid-etched (SLA) and 48 machined titanium disks were contaminated with oral bacterial biofilm and exposed to the following treatments: (1) titanium brush (TB), (2) TB + 40% citric acid (CA), (3) TB + 5.25% sodium hypochlorite (NaOCl), (4) air polishing with glycine powder (AP), (5) AP + 40% CA, and (6) AP + 5.25% NaOCl. Residual bacteria and chemical contamination were assessed using viable bacterial count assay, scanning electron microscopy (SEM), and x-ray spectroscopy (XPS). Human primary osteoblast (hOB) adhesion and osteocalcin (OC) release were also evaluated. The microbiologic, SEM, and XPS analysis indicate a higher biofilm removal efficiency of combined mechanical-chemical treatments compared with exclusively mechanical approaches, especially on SLA surfaces. SEM analysis revealed significant alterations of surface microtopography on the disks treated with TB, while no changes were observed after AP treatment. OC release by hOBs was mainly decreased on disks treated with CA and NaOCl. The combination of mechanical and chemical treatments provides effective oral biofilm removal on both SLA and machined implant surfaces. NaOCl and CA may have a negative effect on osteoblasts cultured on SLA samples.

The surface finish of a pattern is vital in any casting process. The mould replicates whatever kind of surface condition the master pattern offers. Therefore, to produce castings with good surface finish, the master pattern made by Fused Deposition Modelling (FDM) must have better surface quality. However, in the FDM process, the surface finish of the parts produced is found to be inferior as compared to wax. To enhance its surface quality, different attempts have been made by several researchers by controlling different process parameters. In this study, an attempt has been made to observe the influence of chemical treatment and FDM process parameters on surface roughness of Acrylonitrile Butadiene Styrene (ABS) patterns to be used for investment casting. Design of Experiments (DOE) and Analysis of Variance (ANOVA) were used to statistically analyse the significant parameters and their interactions. From the analysis, the best process parameters were predicted. Results also showed that substantial improvement in surface quality of FDM patterns can be obtained with simple inexpensive chemical treatments.

Chemical treatment can effectively reduce the surface roughness of fused deposition modeling (FDM) parts. An effort is made in this study to appraise the surface finish of poly lactic acid (PLA) parts by FDM with hot vapor smoothing treatment. The tests were designed as per the Taguchi L16 orthogonal array based factorial design of experimentation while varying process parameters such as time, temperature and solution concentration of hot vapor smoothing. The surface roughness of PLA parts after chemical treatment reduces in different degrees compared with FDM prototypes. The results of the statistical study indicate that the surface roughness is affected by treatment temperature. The optimum parameters that have been verified by performing the experiments may provide a theoretical basis for FDM parts in practical application.

Fused deposition modeling (FDM) is an extrusion-based AM process that is widely used due to its cost-effectiveness and user friendly. However, FDM also has some limitations such as the appearance of seam lines between layers and the production of excess material residue leading to poor surface finish, poor bonding between layers and porosity. This paper presents the findings on the application of ultrasonic vibration in an open-source FDM 3D printer to investigate its effect on the mechanical properties and microstructure of acrylonitrile butadiene styrene (ABS) and Polylactic Acid (PLA) samples. Two units of ultrasonic piezoelectric transducer were clamped horizontally on the surface of the 3D printer platform. The ultrasonic vibration was transmitted directly to the platform while the sample received vibration with a specific frequency while the printing process commences. Two process parameters, namely build orientation and ultrasonic vibration were selected to analyze their significance and optimization on the mechanical properties and the microstructure of the printed samples. High compressive and low surface roughness are required to have the best properties for the printed sample. Therefore, the optimization parameters are performed with these settings where the compressive strength is maximized and the surface roughness is minimized. The result shows that the overall compressive strength in ABS and PLA samples created in the Z-axis orientation is higher than in the X-axis orientation. However, the compressive strength of ABS and PLA samples is not much different after the ultrasonic vibration was applied during the printing process. The microstructure analysis shows that bonding between the layers is similar when applying ultrasonic vibration for both ABS and PLA samples. Furthermore, the result indicates that the surface roughness increased at 10 kHz and then decreased or became smoother at 20 kHz for both ABS and PLA material samples. The analysis shows that the build orientation significantly affects the compressive strength in ABS and PLA samples. However, the ultrasonic vibration has no considerable impact. In surface roughness, the build orientation and ultrasonic vibration significantly affect ABS samples. However, the PLA samples are only slightly affected. The optimum parameters for both materials are found where Z-axis orientation and 0 kHz of the ultrasonic vibration samples gave the best compressive strength and surface roughness value.

Fused filament fabrication (FFF) has seen an upsurge in its utilization towards development of tailored made materials of polymer base. The advancement and diversity in fabricating the polymer composite parts by using FFF has seen the embracement of this technology in wider aspects, ranging from automotive, aerospace, construction and has marched towards day to day requirements. This research article focuses on development of polymer composite; by using flyash (FA), an industrial waste produced during coal combustion, as reinforcement in Acrylonitrile butadiene styrene (ABS) matrix, to study the physical and mechanical properties. FA, which is primarily made up of metal oxides, plays an imperative role as reinforcement. Easily and abundantly available, FA is being used in several applications to reduce the landfills utilization and also helps the environment. In this study FA was added as reinforcement in 5 and 10 wt. % respectively to ABS matrix and was developed into filament of 1.75 mm diameter. The developed ABS + FA polymer composite using FFF, were analyzed for physical and mechanical properties as per American Society for Testing and Materials (ASTM) standards. Microstructure studies were carried out for the developed composite to understand their behavior in enhancing the dimensional accuracy and tensile strength with incremental addition of FA up to 10 wt%. Tensile strength was enhanced by 28.19% and 36.13% for ABS + 5wt. % FA and ABS + 10wt. % FA respectively. Dimensional stability was also enhanced. Similarly, surface roughness analysis was carried out and it was observed to reduce with addition of FA. The surface roughness measurements provided suitable results of decrement by 9.64% and 14.6% for ABS + 5wt. % FA and ABS + 10wt. % FA respectively. Overall, the usage of FA along with FFF, has paved a path in sustainable and green technology in manufacturing.

The fused deposition modelling (FDM) assisted investment casting (IC) is one of the commercially established routes for fabrication of biomedical parts requiring high precision. In past two decades number of studies has been reported on use of thermoplastic and wax based FDM patterns for IC of dental crown (DC) in human dentistry. But hitherto little has been reported on comparison of Ni-Co-Cr based DC prepared by using FDM printed virgin acrylonitrile butadiene styrene (ABS) pattern and wax coated ABS pattern for veterinary patients (VP). In this work, first molar and canine teeth in left side of lower mandible of a 3-year German Shepherd male dog has been prepared by using virgin ABS and wax coated ABS patterns followed by IC of Ni-Co-Cr alloy. The result of study suggests that wax coated ABS samples-based DC has better surface hardness, grain structure, surface roughness (Ra) and controlled surface porosity thus may be used as commercial manufacturing strategy. The results have been supported with scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis.