scholarly journals Optimization of FFF Processing Parameters to Improve Geometrical Accuracy and Mechanical Behavior of Polyamide 6 Using Grey Relational Analysis (GRA)

2021 ◽  
Author(s):  
Zohreh Shakeria ◽  
Khaled Benfriha ◽  
Nader Zirak ◽  
Mohammadali Shirinbayan
Keyword(s):  
Layer Thickness ◽  
Process Parameters ◽  
Complex Geometry ◽  
Gray Relational Analysis ◽  
Optimum Process ◽  
Optimal Parameters ◽  
Fused Filament Fabrication ◽  
Geometrical Accuracy ◽  
Relational Analysis ◽  
Chamber Temperature

Abstract One of the most widely used additive manufacturing (AM) methods is Fused Filament Fabrication (FFF), which can produce complex geometry parts. In this process, a continuous filament of thermoplastic material is deposited layer by layer to make the final piece. One of the essential goals in the production of parts with this method is to produce parts with high mechanical properties and excellent geometrical accuracy at the same time. Among the various methods used to improve the desired properties of produced parts is to determine the optimum process parameters in this process. This paper investigates the effect of different process parameters on four essential parameters: chamber temperature, Printing temperature, layer thickness, and print speed on cylindricity, circularity, strength, Young’s modulus, and deformation by Gray Relational Analysis method simultaneously. Taguchi method was used to design the experiments, and the PA6 cylindrical parts were fabricated using a German RepRap X500® 3D printer. Then the GRG values were calculated for all experiments. In the 8th trial, the highest value of GRG was observed. Then, to discover the optimal parameters, the GRG data were analyzed using ANOVA and S/N analysis, and it was determined that the best conditions for enhancing GRG are 60 °C in the chamber temperature, 270 °C in the printing temperature, 0.1 mm layer thickness, and 600 mm/min print speed. Finally, by using optimal parameters, a verification test was performed, and new components were investigated. Finally, by comparing the initial GRG with the GRG of the experiment, it was discovered that the GRG value had improved by 14%.

scholarly journals Optimisation of Strength Properties of FDM Printed Parts—A Critical Review

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1587
Author(s):  
Daniyar Syrlybayev ◽  
Beibit Zharylkassyn ◽  
Aidana Seisekulova ◽  
Mustakhim Akhmetov ◽  
Asma Perveen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Layer Thickness ◽  
Process Parameters ◽  
Fused Deposition Modeling ◽  
Complex Geometry ◽  
Positive Impact ◽  
Dimensional Accuracy ◽  
Strength Properties ◽  
Fused Filament Fabrication ◽  
Fused Deposition

Additive Manufacturing is currently growing fast, especially fused deposition modeling (FDM), also known as fused filament fabrication (FFF). When manufacturing parts use FDM, there are two key parameters—strength of the part and dimensional accuracy—that need to be considered. Although FDM is a popular technology for fabricating prototypes with complex geometry and other part product with reduced cycle time, it is also limited by several drawbacks including inadequate mechanical properties and reduced dimensional accuracy. It is evident that part qualities are greatly influenced by the various process parameters, therefore an extensive review of the effects of the following process parameters was carried out: infill density, infill patterns, extrusion temperature, layer thickness, nozzle diameter, raster angle and build orientation on the mechanical properties. It was found from the literature that layer thickness is the most important factor among the studied ones. Although manipulation of process parameters makes significant differences in the quality and mechanical properties of the printed part, the ideal combination of parameters is challenging to achieve. Hence, this study also includes the influence of pre-processing of the printed part to improve the part strength and new research trends such as, vacuum-assisted FDM that has shown to improve the quality of the printing due to improved bonding between the layers. Advances in materials and technologies that are currently under development are presented. For example, the pre-deposition heating method, using an IR lamp of other technologies, shows a positive impact on the mechanical properties of the printed parts.

Mechanical Behaviour of Polylactic Acid Parts Fabricated via Material Extrusion Process: A Taguchi-Grey Relational Analysis Approach

2020 ◽  
Vol 46 ◽  
pp. 32-44
Author(s):  
Peter Kayode Farayibi ◽  
Babatunde Olamide Omiyale
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Layer Thickness ◽  
Polylactic Acid ◽  
Process Parameters ◽  
Grey Relational Analysis ◽  
Extrusion Temperature ◽  
Relational Analysis ◽  
Grey Relational

The acceptance and application of functional parts produced via additive manufacturing technologies is faced with challenges of poor surface finish, dimensional accuracy and mechanical properties among other which is mostly dependent on process parameters employed. In this study, the effect of infill density, layer thickness and extrusion temperature on mechanical properties of polylactic acid (PLA) part manufactured using fused deposition modelling process was investigated to obtain optimum process parameters to achieve the best properties. Solid cuboid bars were produced from which tensile, impact and hardness test specimens were obtained. A statistical approach based on Taguchi design of experiment was employed with process parameters varied and grey relational analysis coupled with principal component analysis was employed to obtain the unified optimum parameter. The single optimisation results showed that 50% infill density, 220°C extrusion temperature and 0.4 mm layer thickness resulted in best tensile strength; 30% density, 210°C temperature and 0.2 mm layer thickness is required to achieve the best impact strength, while 50% density, 215°C temperature and 0.3 mm thickness is required for highest hardness. The multi-response optimisation indicated that for the best of all the three properties to be achieved at once in a PLA built part, 50% infill density, 220°C extrusion temperature and 0.3 mm is required which yielded tensile strength of 30.02±2.15 MPa, impact strength 4.20±0.12 J and hardness of 76.80±0.38 BHN.

Optimization of Process Parameters of Pulsed Electro Deposition Technique for Nanocrystalline Nickel Coating Using Gray Relational Analysis (GRA)

2017 ◽  
Vol 17 (01n02) ◽  
pp. 1760007
Author(s):  
C. Venkatesh ◽  
N. Sundara Moorthy ◽  
R. Venkatesan ◽  
V. Aswinprasad
Keyword(s):  
Grain Size ◽  
Process Parameters ◽  
Surface Engineering ◽  
Nickel Coating ◽  
Pulse Frequency ◽  
Gray Relational Analysis ◽  
Average Current Density ◽  
Electro Deposition ◽  
Relational Analysis ◽  
Nano Nickel

The moving parts of any mechanism and machine parts are always subjected to a significant wear due to the development of friction. It is an utmost important aspect to address the wear problems in present environment. But the complexity goes on increasing to replace the worn out parts if they are very precise. Technology advancement in surface engineering ensures the minimum surface wear with the introduction of polycrystalline nano nickel coating. The enhanced tribological property of the nano nickel coating was achieved by the development of grain size and hardness of the surface. In this study, it has been decided to focus on the optimized parameters of the pulsed electro deposition to develop such a coating. Taguchi’s method coupled gray relational analysis was employed by considering the pulse frequency, average current density and duty cycle as the chief process parameters. The grain size and hardness were considered as responses. Totally, nine experiments were conducted as per L9 design of experiment. Additionally, response graph method has been applied to determine the most significant parameter to influence both the responses. In order to improve the degree of validation, confirmation test and predicted gray grade were carried out with the optimized parameters. It has been observed that there was significant improvement in gray grade for the optimal parameters.

Multi-Objective Optimization of EDM Process Parameters using Taguchi Method, Principal Component Analysis and Grey Relational Analysis

2014 ◽  
Vol 4 (2) ◽  
pp. 29-46 ◽  
Author(s):  
U. Shrinivas Balraj ◽  
A. Gopala Krishna
Keyword(s):  
Principal Component Analysis ◽  
Taguchi Method ◽  
Process Parameters ◽  
Grey Relational Analysis ◽  
Electrical Discharge Machining ◽  
Principal Component ◽  
Component Analysis ◽  
Optimum Process ◽  
Relational Analysis ◽  
Grey Relational

This paper investigates multi-objective optimization of electrical discharge machining process parameters using a new combination of Taguchi method and principal component analysis based grey relational analysis. In this study, three conflicting performance characteristics related to surface integrity such as surface roughness, white layer thickness and surface crack density are considered in electrical discharge machining of RENE80 nickel super alloy. The process parameters considered are peak current, pulse on time and pulse off time. The experiments are conducted based on Taguchi method and these experimental results are used in grey relational analysis and weights of the corresponding performance characteristics are determined by principal component analysis. The weighted grey relational grade is used as a performance index to determine optimum process parameters and results of the confirmation experiments indicate that the combined approach is effective in determining optimum process parameters.

scholarly journals Optimization of Bio Degradable Nano Cutting Fluid Parameters during Machining of Titanium Alloy

2020 ◽  
Vol 8 (6) ◽  
pp. 2378-2384
Keyword(s):  
Research Work ◽  
Nano Particles ◽  
Cutting Fluid ◽  
Gray Relational Analysis ◽  
Cutting Fluids ◽  
Nano Particle ◽  
Optimal Parameters ◽  
Relational Analysis ◽  
Confirmation Test ◽  
Fluid Parameters

Varieties of cutting fluids are available in market to facilitate good machining objectives for metal removing Industries. Eventually, majority of the cutting fluids are synthetic and semi synthetic in nature, despite they are helping to the industries but they are harmful to health of the operators and environment. Though they are having good properties needed for machining, nature of non-biodegradability and non-friendliness to the environment are the key barriers associated with these fluids. Various researches have been carried out to prepare a vegetable based bio degradable effective cutting fluid to nullify above said constraints. In this research work, a unique castor oil based cutting fluid infused with nano molybdenum di sulfide (MoS2) particles has been prepared and its performance during machining has been investigated. In this study, much attention has been applied to achieve the optimized parameters of the biodegradable nano cutting fluid. Taguchi's method equipped with gray relational analysis was utilized by considering the size of the nano particles, nano particle inclusion (npi) and flow rate as the chief fluid parameters. The surface roughness and tool wear were treated as responses. As per L9 orthogonal array, totally nine experiments were conducted. Additionally, the most significant parameter which affects the machining responses was identified with the help of grey grade, ANOVA and MRPI ranking. Confirmation test were carried out followed by prediction of grey grade so as to improve the degree of validation. It has been observed that there was significant improvement in gray grade for the optimal parameters.

Process–Property Relationships for Fused Filament Fabrication on Preexisting Polymer Substrates

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Harry A. Pierson ◽  
Bharat Chivukula
Keyword(s):  
Surface Roughness ◽  
Bond Strength ◽  
Layer Thickness ◽  
Process Parameters ◽  
Optimal Parameter ◽  
Fused Filament Fabrication ◽  
Highly Sensitive ◽  
Raster Angle ◽  
Process Property ◽  
Five Axis

Recent advances in fused filament fabrication (FFF), such as five-axis printing, patching existing parts, and certain hybrid manufacturing processes, involve printing atop a previously manufactured polymer substrate. The success of these technologies depends upon the bond strength between the substrate and the newly added geometry. ANOVA and response surface methods were used to determine the effect of three process parameters on bond tensile strength: surface roughness, layer thickness, and raster angle. Experimental results indicate that the process–property relationships are not identical to those found in single, continuous FFF operations, and that the physical bonding mechanisms may also be different. Bond strength was found to be highly sensitive to surface roughness and layer thickness, and distinct optimal parameter settings exist. These results represent a first step toward understanding bond strength in such circumstances, allowing manufacturers to intelligently select process parameters for the production of both the substrate and the secondary geometry.

scholarly journals Grey Relational Analysis to Determine the Optimum Process Parameters for Open-End Spinning Yarns

2012 ◽  
Vol 7 (2) ◽  
pp. 155892501200700 ◽  
Author(s):  
Hossein Hasani ◽  
Somayeh Akhavan Tabatabaei ◽  
Ghafour Amiri
Keyword(s):  
Taguchi Method ◽  
Process Parameters ◽  
Grey Relational Analysis ◽  
Raw Materials ◽  
Performance Characteristics ◽  
Optimum Process ◽  
Rotor Speed ◽  
Relational Analysis ◽  
Grey Relational Grade ◽  
Grey Relational

This article focuses on an approach based on the Taguchi method with grey relational analysis for optimizing the process parameters for open-end spun yarns with multiple performance characteristics. A grey relational grade obtained from the grey relational analysis is used to optimize the process parameters. Optimal process parameters can then be determined by the Taguchi method using the grey relational grade as the performance index. CVm%, hair number per meter, and tenacity of yarn were selected as quality characteristics. Using these characteristics, the process parameters, including rotor speed, rotor diameter, opener speed, yarn linear density and navel type are optimized. The raw materials used in this investigation were cotton fibers (35%) and cotton waste (65%) collected from ginning machines. The Experimental results show parameter rotor speed has the most significant effect on the multiple performance characteristics.

scholarly journals Prediction and analysis of surface roughness in selective inhibition sintered high-density polyethylene parts: A parametric approach using response surface methodology–grey relational analysis

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401882099 ◽  
Author(s):  
D Rajamani ◽  
Aiman Ziout ◽  
E Balasubramanian ◽  
R Velu ◽  
Salunkhe Sachin ◽  
...  
Keyword(s):  
Layer Thickness ◽  
Surface Quality ◽  
Process Parameters ◽  
Grey Relational Analysis ◽  
High Density Polyethylene ◽  
Selective Inhibition ◽  
Optimal Process ◽  
Relational Analysis ◽  
Selective Inhibition Sintering ◽  
Grey Relational

Selective inhibition sintering (SIS) process intends to produce near-net-shape components through sintering of specific region of powder particles. The prediction of surface quality in SIS parts is a challenging task due to its complex part building mechanism and influence of abundant process parameters. Therefore, this study investigates the key contributing parameters such as layer thickness, heater energy, heater feedrate and printer feedrate on the surface quality characteristics ( Ra, Rz and Rq) of high-density polyethylene specimens fabricated through selective inhibition sintering process. The SIS system is custom built and experiments are conducted based on four-factor, three-level Box–Behnken design. The empirical models have been developed for predicting the influence of selected parameters on surface quality. The optimal process parameters such as the layer thickness of 0.1 mm, heater energy of 28.48 J/mm2, heater feedrate of 3.25 mm/s and printer feedrate of 110 mm/min are attained using grey relational multi-criteria decision-making approach. Furthermore, response surface analysis revealed that surface quality of sintered components is influenced significantly with heater energy and heater feedrate, followed by layer thickness. The confirmation experiments based on optimal process variables validate the developed grey relational analysis strategy.

Effect of processing variables on mechanical properties of montmorillonite clay/unsaturated polyester nanocomposite using Taguchi based grey relational analysis

2012 ◽  
Vol 32 (8-9) ◽  
pp. 555-566 ◽  
Author(s):  
Nagarajan Rajini ◽  
Jebas Thangaih Winowlin Jappes ◽  
Sivaprakasam Rajakarunakaran ◽  
Irullappasamy Siva
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Process Parameters ◽  
Grey Relational Analysis ◽  
Unsaturated Polyester ◽  
Optimum Process ◽  
Blade Design ◽  
Process Variables ◽  
Relational Analysis ◽  
Grey Relational

Abstract The present investigation addresses the influence of process variables on the mechanical properties of montmorillonite (MMT) nanoclay with unsaturated polyester, using the mechanical shear mixing process. The rotational speed, mixing time, rotor blade design and clay content were chosen as process variables. The influence of these process variables on mechanical properties were studied with the help of grey relational analysis. Organically modified MMT nanoclay was used as the reinforcing filler, in order to increase the swelling of the clay with the polyester resin. Nanocomposites were fabricated based on the experimental design using the L9 orthogonal array. Among the parameters studied, blade design was identified as the parameter with the most influence, due to the presence of a varying shear force, which peeled off the clay platelets from the stacked arrangement of clay tactoids. Grey relational analysis was used to obtain the optimum process parameters for multiple quality characteristics such as tensile, flexural and impact strength. It was observed that the Shore D hardness values for all nine experiments possess higher values than virgin polyester. Morphological studies have been carried out for the specimen with optimum process parameters using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Tensile, flexural and impact fractured specimens were studied using scanning electron microscopy (SEM) for optimum conditions.

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