Wear Behaviour of Tungsten Carbide in End Milling Process of Aluminium Alloy 6061-T6 with Minimal Quantity of Tri-hybrid Nanofluids
Abstract
Nowadays, using nanotechnology in science and industry improves the yield of different processes. The machining process using hybrid nanofluids requires further research to better understand the mechanism of tool wear and the fundamental aspects are not yet ventured. In machining, tool wear is common problems that exist for quite some time. In addition, milling process of Aluminium Alloy was challenged due to a strong adhesion particularly in higher temperature. Deposition of chips material during the process at the tool edge may induce several tool failures such as build-up edge, chipping and flaking. Eventually, tool life, manufacturing cost and product quality were the factors that normally effects by tool wear. However, the severity of tool wear can be reduced by applying a cutting fluid to the tool-workpiece interface. This paper intends to discover the effects of tri-hybrid nanofluids in end milling process of Aluminium Alloy 6061-T6 mainly on wear conditions of uncoated and double-layered PVD coated inserts. In this research works, three different nanoparticles SiO2-Al2O3–ZrO2 were dispersed in 60:40 of deionized water and ethylene glycol. The concentration was prepared between 0.06 and 0.12 wt.%. The MQL system with assisted air pressure was employed to deliver newly developed tri-hybrid nanofluids. During metal cutting process, the metal working fluid was supplied intermittently based on flow rate setting in the MQL system to the cutting zone with a very minimal quantity. A single insert was used and changed for every 100 mm of cutting length at different machining parameters. The effects on wear mechanisms were closely examined at the flank area using scanning electron microscope. Through comprehensive investigation, the wear mechanisms consist of attrition, flaking, abrasion and coating delamination. Other phenomenon such as thermal crack was observed in the wear region. The tool failures have a relationship with machining parameters and cutting tool condition itself. It can be concluded that, coating delamination and abrasion quite severe for coated inserts. While, uncoated tools were severe with attrition mode of failures. At extreme machining condition, higher temperature and friction forces at the tool-workpiece interface have a significant effect on the tool failures. For further investigation, the effects of tri-hybrid nanofluids on wear behaviour of tungsten carbide inserts can be examined for other machining process with different workpiece material.
ResearchGate has not been able to resolve any citations for this publication.
Overlapping melting trajectories and partially-melted powders result in poor surface morphology and high surface roughness values (Ra = ~13.34 μm) of selective laser melted (SLMed) Ti6Al4V alloy. Secondary processing of SLMed components is thus an essential finishing operation to produce functional SLMed parts in precision engineering. This paper investigates the effects of laser scanning strategies (0°, 67.5° and 90° laser scanning schemes) and machining surfaces (top and front surfaces) on the machining performance of SLMed Ti6Al4V alloy in milling, compared to that of annealed ASTM B265 Ti6Al4V alloy. Results indicated that the high degree of anisotropy of SLMed Ti6Al4V alloy is reflected in cutting force, surface morphology and surface roughness on different machining surfaces during milling. The machining anisotropy is dominated by the anisotropy of microstructure and mechanical properties of SLMed Ti6Al4V alloy, where the anisotropy weakens following the sequence of 0°, 90° and 67.5° SLMed samples. It is verified that high cutting speed can improve machining anisotropy features of SLMed titanium alloy. The chip shape of SLMed Ti6Al4V alloy is a typical conical spiral chip, and the bending degree and length of chips produced by SLMed Ti6Al4V alloy are larger than those of chips produced by annealed Ti6Al4V alloy.
Chip morphology and its formation mechanisms, cutting force, cutting power, specific cutting energy, tool wear, and tool wear mechanisms at different cutting speeds of 100–3000 m/min during dry face milling of Ti-6Al-4V alloy using physical vapor deposition-(Ti,Al)N-TiN-coated cemented carbide tools were investigated. The cutting speed was linked to the chip formation process and tool failure mechanisms of the coated cemented cutting tools. Results revealed that the machined chips exhibited clear saw-tooth profile and were almost segmented at high cutting speeds, and apparent degree of saw-tooth chip morphology occurred as cutting speed increased. Abrasion in the flank face, the adhered chips on the wear surface, and even melt chips were the most typical wear forms. Complex and synergistic interactions among abrasive wear, coating delamination, adhesive wear, oxidation wear, and thermal mechanical–mechanical impacts were the main wear or failure mechanisms. As the cutting speed was very high (>2000 m/min), discontinuous or fragment chips and even melt chips were produced, but few chips can be collected because the chips easily burned under the extremely high cutting temperature. Large area flaking, extreme abrasion, and serious adhesion dominated the wear patterns, and the tool wear mechanisms were the interaction of thermal wear and mechanical wear or failure under the ultra-high frequency and strong impact thermo-mechanical loads.
Base on the development practice of carbide milling cutter used for high speed machining of aluminum alloy, through the empirical analysis of the failure mechanism of milling cutter, and combined with the cutting performance of high strength aluminum alloy and the stress strain characteristics of cutter on high speed condition, the design principle, manufacture and using technology of carbide milling cutter for high speed machining of aluminum alloy are discussed in detail.
This paper investigates the minimum quantity lubrication technique in end milling of aluminum alloy AA6061 with minimum quantity lubrication (MQL) conditions using nanofluid. Wear mechanisms for the water-based TiO2 nanofluid with a nanoparticle volume fraction of 1.5 % are compared with conventional oil-based minimum quantity lubrication (0.48 and 0.83 ml/min) and flooded cooling conditions using an uncoated tungsten carbide insert. Wear mechanisms are characterized. Results show adhesion of the work material as the major tool damage phenomenon. Abrasion wear is also observed along with adhesion. The major benefit from the water-based nanofluid MQL is shown in the intact edge geometry, i.e., edge integrity showing very little chipping as well as edge fracture. This is attributed to the cooling effect produced by the latent heat of vaporization of water, resulting in lowering of temperature in the cutting zone.
In this study, the effect of artificial aging on the machinability of 6061 Al-alloy was investigated for the as-received, solution heat treated (SHT) and solution heat treated and then aged (SHTA) conditions. The experimental work has revealed that different aging times at 180°C and the cutting speed significantly affected the machined surface roughness values. However, cutting forces were not influenced significantly by aging and cutting speed except for SHT workpieces having the lowest hardness.
Selective laser melting (SLM) shows significant advantages in near net-shaped manufacturing of metal components with complex geometries. However, subsequent post-machining is usually conducted for the improvement of surface quality and dimensional accuracy of SLMed parts. This paper focuses on the precision machining performance of SLMed Ti6Al4V alloys and wear mechanism of multi-layered TiAlN/AlCrN coated carbide tools. The influence of laser scanning schemes, machining surfaces as well as lubrication conditions (dry and MQL) on machinability of SLMed Ti6Al4V alloys in terms of cutting force, surface quality, tool wear morphology and wear mechanism was evaluated and analyzed. The results indicate that, the largest difference in cutting force and surface roughness between the top and front surfaces under dry cutting occurred in 0°-linear SLMed Ti6Al4V alloy due to its prominent anisotropic features. Compared to the surface quality in dry cutting, the improvement of surface roughness of SLMed Ti6Al4V alloys under MQL is up to 82.2%, which was significantly superior to the 59.2% improvement of annealed titanium alloy. Because of the improvement of tribological properties between the flank and machined surface, adhesive wear becomes the primary wear mechanism of TiAlN/AlCrN coated carbide tools under MQL during precision machining of SLMed Ti6Al4V alloys, while abrasive wear is the main wear mechanism under dry cutting. In addition, the ductility and integrity of ribbon chips derived from SLMed Ti6Al4V alloys are superior to those of chips originating from annealed titanium alloy, where significant tearing and cracking occurred in the chips of annealed titanium alloy.
Elevated temperature experienced in the cutting zone is the main issue contributing to severe wear and responsible in reducing the lifespan of cutting tools'. This study aims to improve the performance of the cutting tool by applying AlCrN coating on the WC-Co substrate using physical vapor deposition (PVD). Prior to the coating process, the WC-Co surface was chemically roughened by Murakami's solution, followed by Caro's solution for 10s. The etched substrates were coated with AlCrN at various PVD deposition temperatures. The scanning electron microscopy (SEM) showed the coating thickness increased from 1.24 μm to 2.78 μm. X-ray diffraction (XRD) pattern confirmed that both AlN and CrN phases dominated the coating layer indicated the presence of AlCrN coating. These XRD peaks were broader, indicating a smaller grain size (11.5 nm) produced at higher deposition temperatures. Apart from that, a minute amount of the Cr2N phase is also detected. The average compressive residual stresses ranged from −5.409 GPa to −1.707 GPa attributed to increased coating thickness associated with Cr2N+N2 → CrN phase transformation. There are no cracking and coating delamination observed at this state. The mechanical properties of the coated structure were further evaluated via Vickers microhardness and linear reciprocating tests. The hardness obtained ranged from 600 to 1617 HV0.2. While the coefficient of friction (CoF) measured was 0.21 after 240 m of sliding distance. The calculated wear rate was 2.283×10⁻⁴ mm³/N·m which exhibited a significant reduction in wear when coated at 450 °C compared to 4.550×10⁻⁴ mm³/N·m at a lower temperature (250 °C). Therefore, it can be concluded that the effect of roughened substrate and various PVD deposition temperatures have significantly influenced the coating phase formation, which subsequently effects the hardness and wear performance of AlCrN-coated tungsten carbide.
The purpose of this study is to investigate solid lubricant-assisted cutting fluids applied through minimum quantity lubrication technique (MQL) for nano-finishing of AISI 4340 steel using TiCN/Al 2 O 3 /TiN chemical vapor deposition coated tungsten carbide inserts during flat end milling process. Four different types of cutting fluids were examined, namely pure emulsion, boric acid dissolved in the emulsion, graphite suspended in the emulsion and hybrid solid-liquid minimum quantity lubrication. Optimization of the flat end milling process was done through single performance Taguchi analysis as well as through a multi-performance Taguchi-Gray relational analysis (TGRA). The hybrid TGRA technique was utilized to get the optimum level of input parameters and to get the knowledge about the significance of the input parameters considering both of the responses simultaneously. The results of the hybrid analysis were confirmed by multi-objective genetic algorithm. Novel and physically based analytical interpretation of the results was provided. Low viscosity fluids were found to provide better results during MQL application. The results lead to cleaner and sustainable production aiming at reducing/omitting waste and making the process environment-friendly.
In this work, microstructure of Ti(C,N)-based cermets can be designed and controlled with extra carbon additions. The influences of microstructure on the mechanical properties and wear mechanism of cermets tools are investigated systematically by scanning electron microscope, X-ray diffraction and machining test of 7075 aluminum alloys. The increasing carbon additions in cermets can react with alloy elements dissolved in binder phase of cermets and promote the formation of rim phase, which may induce the disappearance of Co3W3(C,N) phase (η phase), reduction of core phase content and increase of rim phase content. With increasing carbon additions, the hardness of cermets decreases slightly, while transverse rupture strength of cermets can increase firstly and then decrease. Moreover, increasing carbon additions can augment the friction coefficient of Ti(C,N)-based cermets, which may induce improvement of cutting temperature and aggravation of abrasion at a relatively low cutting speed. However, with increasing cutting speeds, the existence of Co3W3(C,N) phase in cermets tools can accelerate wear process of tools.
Nanofluids have found crucial presence in heat transfer applications with their promising characteristics that can be controlled as per requirements. Nanofluids possess unique characteristics that have attracted many researchers over the past two decades to design new thermal systems for different engineering applications. Mono nanofluids, prepared with a single kind of nanoparticles, possess certain specific benefits owing to the properties of the suspended nanoparticle. However to further improve the characteristics of nanofluids, that could possess a number of favourable characteristics, researchers developed a new generation heat transfer fluid called hybrid nanofluid. Hybrid nanofluids are prepared either by dispersing dissimilar nanoparticles as individual constituents or by dispersing nanocomposite particles in the base fluid. Hybrid nanofluids may possess better thermal network and rheological properties due to synergistic effect. Researchers, to adjudge the advantages, disadvantages and their suitability for diversified applications, are extensively investigating the behavior and properties of these hybrid nanofluids. This review summarizes the contemporary investigations on synthesis, thermo-physical properties, heat transfer characteristics, hydrodynamic behavior and fluid flow characteristics reported by researchers on different hybrid nanofluids. This review also outlines the applications and challenges associated with hybrid nanofluid and makes some suggestions for future scope of research in this area.