12 research outputs found
Optimization of cutting parameter for machining Ti-6Al-4V titanium alloy
Titanium alloy Ti-6Al-4V, has been broadly used in industries, primarily medical manufacturing, and aerospace, due to their considerable mechanical properties. Aerospace structural components made of titanium alloy (Ti-6Al-4V) material, a difficult-to-machine material which results in massive cutting force, steep cutting temperature, and significant tool wear. In this research, carbide insert tool is used to cut a Ti-6Al-4V titanium block at constant depth of cut of 0.50 mm using the method of dry machining is investigated with the aim of estimating the effects of two manipulated cutting parameters, which are spindle speed (140 and 150 m/min), and feed rate (0.1 and 0.2). This was done to observe their effects on the tool wear of the insert. The objective of this study is to study the machinability performance of coated carbide insert tool under dry machining condition, and to optimize the cutting parameter to machine Ti-6Al-4V using dry machining method. It was found in this research that lowest valued parameter, Parameter 1 (140 m/min, 0.1 mm/rev) caused the most flank wear, and the roughest surface on the Ti-6Al-4V block. Lower speeds can possibly inflict higher shocking force, which leads to higher wear propagation
Engineered nanomaterials for aviation industry in COVID-19 context: A time-sensitive review
Engineered nanomaterials (ENMs) are catalyzing the Industry 4.0 euphoria in a significant way. One prime beneficiary of ENMs is the transportation industry (automotive, aerospace, rail car), where nanostructured multi-materials have ushered the path toward high-strength, ultra-impact-resistant, lightweight, and functionally graded engineered surfaces/components creation. The present paper aims to extrapolate much-needed ENMs knowledge from literature and its usage in the aviation industry, highlighting ENMs contribution to aviation state-of-the-art. Topics such as ENMs classification, manufacturing/synthesis methods, properties, and characteristics derived from their utilization and uniqueness are addressed. The discussion will lead to novel materials’ evolving need to protect aerospace surfaces from unfolding SARS-COVID-19 and other airborne pathogens of a lifetime challenge
The analysis of grid independence study in continuous disperse of MQL delivery system
A sustainable cutting method of Minimum Quantity Lubricant (MQL) was introduced to promote lubrication effect and improve machinability. However, its performances are very dependent on the effectiveness of its mist to penetrate deep into the cutting zone. Optimizing the MQL system requires massive experimental work that increases cost and time. Therefore, this study conducts Computational Fluid Dynamic (CFD) analysis using ANSYS Fluent and focuses on the grid independence study in dispersed-continuous phase of MQL delivery system. The main aim is to identify the best mesh model that influences the accuracy of the CFD model. The analysis proposed two different unstructured grid cell elements of quadrilateral and triangular that were only applicable for 2-dimensional fluid flow in CFD. The unstructured grid was controlled with three different mesh quality factors such as Relevance Center, Smoothing, and Span Angle Center at coarse /low, medium, and fine /high. The results showed that the best mesh quality for quadrilateral was at 60,000 nodes number and coarse mesh, whereas the triangular was at 90,000 nodes number and coarse mesh. Both combinations resulted the most consistent and reliable result when compared with past studies. However, this study decided to choose quadrilateral cell element with 60,000 nodes number and coarse mesh as it is considered to be sufficient to provide accurate and reliable result as well as practical in terms of computational time for the MQL model in CFD analysis
Mesh independence study on CFD for Cryo-CO2 cooling strategy
This study conducts comprehensive mesh independence tests to identify the optimum mesh independence parameters that offer the most feasible Computational Fluid Dynamic (CFD) analysis on cryo-CO2 temperature variations and its heat transfer performance under cryo-CO2 cooling strategy in metal cutting. ANSYS Fluent was used to conduct the CFD study with its mesh control parameters (relevance center and smoothing) designed using Response Surface Methodology (RSM) under Central Composite Design (CCD). An Analysis of Variance (ANOVA) was applied to analyse how the controlled factors influenced the cryo-CO2 flow temperature when it flowed from the nozzle to the tooltip. The analysis found that the relevance centre was more significant in influencing the accuracy of the response value. For optimization, the combination of medium relevance center and smoothing meshes was suggested to develop the lowest cryo-CO2 flow temperature at 256.85 K. This is crucial since most machining outputs are heat dependent. Experimental data sets were used to validate the predicted result. Distances between 3.6 to 18 mm showed an acceptable deviation of ~0.4 – 0.6% and ~0.4 – 4.2% for simulated and experimented work, respectively. This value is acceptable, and the generated quadratic model equation can be applied for prediction. The heat transfer performance of the cryo-CO2 flow at tool-chip and tool-workpiece interfaces under high-speed machining was also discussed. Moreover, further analysis using the optimal solution has led to a better understanding of heat transfer in cryogenic carbon dioxide (CO2), resulting in enhanced cooling of the cutting zone and improved machining processes
Experimental study on dynamic viscosity of aqueous-based nanofluids with an addition of ethylene glycol
In this study, the effect of adding different nanoparticles in the mixture of deionised water and ethylene glycol on dynamic viscosity is investigated experimentally. In order to prepare for single nanofluids, the dry nanoparticles of SiO2, Al2O3 and ZrO2 were dispersed into 60% volume of deionised water and 40% volume of ethylene glycol as a base fluid using a two-step method. The experiments were performed in the temperature range of 30°C and 70°C and weight fraction ranging between 0.1wt.% and 1wt%. No surfactant used in preparing the nanofluids. The dynamic viscosity data were collected using DV-II+ Pro Brookfield viscometer. The single, dual-hybrid and tri-hybrid aqueous based nanofluids dynamic viscosity results are explicitly presented. From the results, it is exhibited that nanofluid viscosity decreases with increasing liquid temperature and increases with increasing of nanoparticles volume concentration. The viscosity decreases with increasing of deionised water volume percentage in the base fluid. Zirconia single nanofluid at 1wt.% recorded 2.5 times maximum enhancement of viscosity over the base fluid. The results display that single nanofluids have higher dynamic viscosity compared to hybrid nanofluids
Effect Of Cutting Speed On The Carbide Cutting Tool In Milling Inconel 718 Alloy
Tribology is a phenomenon concerning the relative motion between at least two amalgamating surfaces. In the machining process, surface roughness is the most important element for studying this occurrence, which contributes to the evaluation of part quality. This paper will provide detailed analysis for better understanding of tribological during the machining process of Inconel 718 alloy using a multi-layer TiAlN/AlCrN-coated carbide ball end inserted in dry cutting condition. The analysis focused on the relationship of tool wear with cutting temperature, cutting force, and surface integrity. Results found that the cutting temperature increased around 7.5% and surface roughness of machined surface improved about 10.3% when the cutting speed increased. Flaking at the rake face and notching at the flank face were determined as the main tool failures during milling Inconel 718. Furthermore, high friction between the tool–workpiece interfaces during machining was due to the build-up edge (BUE) formation that causes an alteration in microstructure at machine surface
Comparison of dry and cryogenic machining on chip formation and coefficient of friction in turning AISI 4340 alloy steel
Application of cutting fluid that provides both coolant and lubrication properties in manufacturing operations such as turning, milling, grinding and other processes has been proven to improve the machining output in many aspects. In cryogenic machining, liquid nitrogen (LN2) is used as cutting fluid to reduce the temperature generated at the cutting zone. However, there is still an issue being raised on whether LN2 also functions as a good lubricant as it does as an excellent coolant. Therefore, an intensive study on the chip formation during dry and cryogenic turning of AISI 4340 alloy steel has been conducted to examine the effect of LN2 cutting fluid on the reduction of friction between the chip and the tool. Results from calculation of coefficient of friction indicate that application of LN2 during turning is able to help the friction reduction up to 73%. Smaller value of coefficient of friction indicates that the shear angle is larger which results in smaller shear plane area that provides benefits of lower cutting force needed to shear off the chips and lower cutting temperature being generated during the machining process
Temperature at the tool-chip interface in cryogenic and dry turning of AISI 4340 using carbide tool
A localized high temperature area occurring at the tip of the tool during a cutting process can be detrimental and lead to a rapid wear mechanism. This paper presents the effect of a cryogenic application during the machining process on the temperature generated at the tool-chip interface, compared to a dry environment in the turning of the AISI 4340 alloy steel using a coated carbide tool. The cutting temperature was estimated using the Third Wave AdvantEdge software, which then was validated with the turning experiments. A significant reduction of the cutting temperature and the steeper temperature gradients on the cutting edge and the chips were observed in the cryogenic machining, which indicates more effective heat removal from the cutting zone. The sudden cold of -196 °C caused the chips to become hard and brittle, which enhanced the chip breakability during the machining process