Effect Of Microtexture Research Articles

The effects of micro-texture shape on serrated chip geometry in the hardened steel AISI D2 cutting process

Five micro-textures were processed on the rake face of PCBN tools: circular pits, elliptical grooves, transverse grooves, composite grooves, and wavy grooves. The effect of different micro-textures on cutting force, the cutting temperature, the micro-morphology of serrated chips, tool wear and surface roughness were investigated utilizing three-dimensional finite element simulation and cutting tests. The results indicates that micro-textured tools can lower cutting force when compared to non-textured tools, while cutting force varies significantly during the cutting process. Micro-texture can decrease the temperature in the adiabatic shear band, changes the temperature distribution of the rake face, reduce the serrated degree, and increase segmentation frequency. However, it is more prone to cracking. The wear resistance and the surface quality of machined surface of the elliptical grooves and wavy grooves micro-texture are better.

Effect of micro-texture on substrate surface on adhesion performance of electroless Ni[sbnd]P coating

Fabricating textured substrate surfaces is an effective way to improve adhesion at a coating-substrate interface. In this study, the radial ultrasonic vibration assisted turning (RUVT) technique is proposed for the fabrication of complex micro-textures on substrate surfaces before they are coated. Electroless NiP coatings were deposited on substrates with various texture densities and their surface and cross section morphologies were characterized. The bonding properties of the prepared coatings were investigated and compared by scratching and three-point bending tests. The test results confirm that the coating adhesion was improved by the prepared micro-textures. The mechanism involves two aspects: mechanical anchoring at the coating interface and substrate surface wettability. As a result, the complex micro-textures formed by RUVT facilitate bonding between a NiP coating and stainless-steel substrate. Therefore, the RUVT technique is a convenient and controllable way to prepare micro-textures without the risk of thermal damage and warrants further exploration.

The effect of microtexture on the liquid flow over the sheets

This work considers the method of the corrugated sheet arrangement near the column wall with the aim to limit liquid fall on the wall and increase liquid concentration in the near-wall area. Experiments were carried out at the corrugated Koch 1Y packing sheets for various liquid flow rates. This report presents experimental results on the character of liquid flow near the edge of corrugated sheets and the effect of the middle sheet shift from the edge of the packing. The ribs of this sheet are directed downward to the edge of the packing. Test was performed for two positions of the middle sheet: to study the effect of microtexture orientation at the sheet, whose ribs are directed downward to the packing edge, on liquid distribution under the packing. Experiments were carried out for liquid flow rates of 1-12 ml/s.

Research on micro-texture placement position and cutting performance of negative chamfering ball-end milling cutter

In order to optimize the position of the micro-texture on the negative chamfering edge ball-end milling cutter, the experiment of milling titanium alloy with the negative chamfering micro-texture ball-end milling cutter was carried out. The effects of micro-texture at different placement positions (rake and flank faces of cutting tools) on cutting performance were compared when the cutting depth was 0.3 mm, and the effects of negative chamfering and micro-texture parameters on cutting performance of the cutter were studied. Finally, the negative chamfering and micro-texture parameters were optimized based on genetic algorithm. The results show that the micro-texture of the flank face can improve the cutting performance, and the negative chamfering angle and width have the greatest influence on the cutting performance. The parameter optimization results are: the negative chamfering angle is 10.016°, the negative chamfering width is 199.995 μm, the micro-pit diameter is 49.996 μm, the micro-pit spacing is 174.004 μm, and the micro-pit distance from the edge is 109.993 μm. The above research realizes high efficiency and high-quality machining of titanium alloy.

Effects of rake surface texture geometries on the performance of single-point cutting tools in hard turning of titanium alloy

Texturing of cutting tool surfaces is emerging as one of the viable solutions to enhance tribological characteristics during machining. Apart from the cutting regime used, the effectiveness of textured tools also depends on the texture geometries. Accordingly, the present study investigates the effect of four different micro-textures on the rake surface of cutting tool inserts in hard turning of Ti-6Al-4V alloys. It specifically addresses the effect of micro-textures on the tool-chip contact length and chip morphology. This study also compares the experimental tool-chip contact length with a new model proposed for inserts with textures. The effect of different insert texture geometries on chip morphology has been investigated by characterizing the chips produced during the cutting. Further, the effects of texture geometries on the parameters like chip compression ratio and shear angle were examined. A detailed analysis has beeen carried out using inserts with and without micro textures to understand their effect on the mechanics of machining. Quantitative predictions were made on the effectiveness of the texture geometry in reducing the cutting forces and friction during machining.

Titanium Microtexture 101, Part II

Abstract This article, the second in a two-part series on titanium alloys, examines the effects of microtexture on deformation behavior, slip dislocations, and fatigue properties. Part I, which appeared in the April 2021 issue, described microstructural evolution processes that result in microtexture formation.

Effect of micro-textures on lubrication characteristics of spur gears under 3D line-contact EHL model

Purpose The purpose of this paper is to use a combination of numerical simulation and experiment to evaluate the performance of laser surface texturing (LST) in the field of gear lubrication, and to more accurately predict the lubrication characteristics of different surfaces. Design/methodology/approach The method used in this paper is developed on the basis of the deterministic solution of the three-dimensional (3D) mixed elasto-hydrodynamic lubrication (EHL) model and the model parameters are corrected by friction test. The film pressure, film thickness and friction coefficient of different micro-textured tooth surfaces are predicted on the basis of accurate 3D mixed EHL models. Findings The results demonstrate that the micro-texture structure of the tooth surface can increase the local film thickness and enhance the lubricating performance of the tooth surface without drastically reducing the contact fatigue life. The stress distribution and friction characteristics of the tooth surface can be optimized by adjusting the micro-texture arrangement and the size of the micro-textures. Originality/value A new evaluation method using a 3D hybrid EHL model and friction test to predict the lubrication characteristics of LST is proposed, which can effectively improve the processing economy and save time. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2020-0423

Effect of micro textures on the cutting performance of circular saw blade

Effect of micro textures on the cutting performance of circular saw blade

The effect of micro-texture on wear resistance of WC/Co-based tools during cutting Ti-6Al-4V

Titanium alloy as an important material used in the aerospace industry and automotive field has many advantages such as excellent specific strength, good corrosion resistance, and ultra-low temperature performance. However, there are still some difficulties during the cutting of Ti-6Al-4V, such as severe tool wear which reduces the surface quality of work piece. Textures could protect the tool from further wear and improve the tool life, and cutting productivity. In this work, femtosecond laser was used to make textures with different orientations (vertical, parallel, and vertical to the main cutting edge) on the rake face of carbide-tipped cutting tool to research the influence of different textures directions on the cutting performance. The results found that using parallel textured tools could reduce the friction coefficient by 14%. Compared with untextured tools, the rake face wear of parallel textures tools is reduced by 35–70% and surface roughness improved by 29%, which is owned to smallest the tool-chip contact area of tool with parallel microstructure.

Cutting performance of micro-textured PCBN tool

To study the effect of micro-texture on the cutting performance of polycrystalline cubic boron nitride (PCBN) tools, five types of micro-textures (circular pits, elliptical grooves, transverse grooves, composite grooves, and wavy grooves) were applied to the rake surface of PCBN tools by an optical fiber laser marking machine. Through a combination of three-dimensional cutting simulations and experiments, the influences of micro-texture on chip–tool contact area, cutting force, chip morphology, shear angle, and surface roughness during the cutting process were analyzed. The results indicated that the chip–tool contact area and cutting force of both non-textured and micro-textured tools increased with increasing cutting speed, while the shear angle decreased with increasing cutting speed. The chip–tool contact area and cutting force of the five types of micro-textured tools were smaller than those of the non-textured tool. The chip–tool contact area and cutting force obtained by the wavy-groove micro-textured tool were the smallest. The chip radius produced by the five types of micro-textured tools was smaller than that produced by the non-textured tool, and the chip morphology was more stable. The transverse-groove micro-textured tool had a better chip breaking effect. The chip radius generated by the elliptical-groove micro-textured tool was 0.96 cm, while that generated by the wavy-groove tool varied from 0.55 cm to 1.26 cm. The presence of a micro-texture reduced the surface roughness of the workpiece by 11.73%–56.7%. Under the same cutting conditions, the five types of micro-textured tools gave a smaller chip–tool contact area, cutting force, chip radius, and surface roughness and a larger shear angle than the non-textured tool. In addition, the elliptical-groove and wavy-groove micro-textured tools had better cutting performance.

Synergistic effect of micro-textures and MoS2 on the tribological properties of PTFE film against GCr15 bearing steel

Synergistic effect of micro-textures and MoS2 on the tribological properties of PTFE film against GCr15 bearing steel

Micro-texturing by femtosecond laser ablation of a carbonaceous anode for production of fluorine by electrolysis

Micro-texturing of the carbon surface of the anode used for the production of fluorine gas by electrolysis is achieved by ablation using a pulsed laser in the femtosecond range; this avoids oxidation of the carbon during ablation. Samples microstructured on the surface via a grid of parallel and perpendicular grooves were prepared and then studied from an electrochemical point of view coupled with ultra-fast image acquisition to visualize the effect of micro-texturing on the dynamics of the fluorine bubbles. In addition, the quantity of gas formed was measured using an incremental flowmeter on an electrolysis cell. Surface micro-texturing controls both the dynamics and shape of the fluorine bubbles, as well as the electroactive zone. The bubbles, then spherical due to the controlled roughness, have a short residence time (about 1 s) and small sizes (a few mm). These observed changes suggest a different wettability of the carbonaceous anode surface by the fluorine gas or the KF-2 H F electrolyte with a beneficial effect on the electrode performance in terms of Faraday efficiency as opposed to the anode voltage which changes slightly. In addition, thanks to the particular dynamics of the fluorine bubbles, very high current densities of up to 75 A dm−² can be applied.

Enhancing cutting performance of uncoated cemented carbide tools by joint-use of magnetic nanofluids and micro-texture under magnetic field

Abstract In this study, the coupling effect of magnetic nanofluids and micro-textures under magnetic field on the tribological properties of uncoated tool is revealed for the first time. The micro-scale grooves parallel to the main cutting edge were fabricated on the tool rake face by laser processing (named TP), and for comparison the tools without surface texturing (named NT) were also prepared. Magnetic nanofluids with a solid content of 30% (named MN) were prepared as coolant for machining the workpiece, and the conventional cutting fluids (named CC) were also prepared for a comparison. At the same time, the magnetic nanofluids were applied to the cutting area by a novel machining setup, then the turning tests were accomplished to study the coupling effect of micro-texture and magnetic nanofluids (TP + MN) under different magnetic field strengths. The analysis of obtained results (cutting forces, surface roughness of workpiece after turning and tool wear) proves the advantages of the magnetic nanofluids and micro-texture under the magnetic field. In these experiments, under the highest magnetic field strength (40 kA/m), TP + MN has 48.6% lower cutting force and 49.1% lower surface roughness of machined workpiece compared to that of NT + CC. Additionally, the mechanism for the coupling effect of micro-textured tool and magnetic nanofluids under magnetic field wasalso revealed.

WITHDRAWN: Effect of Micro-texture of Flank Surface on Broaching Force and Surface Quality of Workpiece

Abstract The application of surface micro-texture in the field of processing tools has become one of the most effective ways to improve economic efficiency in the manufacturing industry. Broaching, as a highly efficient processing method, is widely used in various industries. In order to improve the cutting performance of broaching tools, three types of surface micro-texture were made on the flank face of broach by Nd: YAG laser: (i) pit in the A1 area (5-14 teeth), (ii) groove in the A2 area (15-24 teeth), (iii) V-type in the A3 area (25-34 teeth), respectively. Then, dry broaching experiments were carried out with a micro-texture broach tool (MBT) and the conventional broach tool (CBT) on the built broaching test system. The results show that compared with the CBT, the MBT tool can effectively reduce the broaching force and improve workpiece surface quality. The largest broaching force of the micro-textured teeth with pit is reduced by 6.62%, while the groove and V-type teeth are 4.84% and 5.63%, respectively. The workpiece surface quality of MBT tool is increased 51.87% compare CBT tool processing. This paper proved that the application of micro-texture on broaches can certainly improve processing quality and reduce energy consumption.

Corrosion Resistance of Micro-Textured Surface Modified Alumina-Titania Coating

Effect of micro-texture on the corrosion resistance of alumina-titania coated mild steel was investigated. The micro-texture was fabricated on the coating surface via laser surface texturing technique. Tafel extrapolation and immersion test was conducted to measure the corrosion resistance and corrosion mechanism of the coating in 3.5% NaCl solution. The results indicated that the micro-texture contributes to a significant improvement of corrosion resistance due to the formation small volume of air trapped in the micro-grooves, which resist the penetration of corrosive ions and reduce the area of solid – liquid interface. The WCA indicated that the textured surface had low wettability. The SEM analysis showed the occurrence of uniform corrosion. The analysis of EDS revealed that there was formation of corrosion product at the coating-substrate interface. In short, the resistance towards corrosion was increased up to 73% indicating that the resistivity of the coating against corrosion was improved by engraving the micro-texture on its surface.

Enhancement of a heat transfer performance on the Al6061 surface using microstructures and fluorine-doped diamond-like carbon (F-DLC) coating

Dropwise condensation (DWC) is one of the most important phenomena to improve the heat transfer performance of steam condensation system. To promote DWC on hydrophilic metals, non-metallic hydrophobic promoters are coated on the surface. Non-metallic coatings are relatively easy to be degraded due to lack of mechanical and chemical properties. In this study, fluorine-doped diamond-like carbon (F-DLC) was used to obtain DWC on Al6061. Prior to F-DLC coating, microtextures were fabricated on Al6061 for the structural wettability control. DWC was successfully obtained with a small size of condensates after the microblasting and nanostructured F-DLC coating on Al6061. The synergic effects of microtextures with Cassie-state contact angle and hydrophobicity of nanostructured F-DLC led the superhydrophobic transformation of the surface. The contact angle increased about 115% from 66° to 142° after the microblasting and nanostructured F-DLC coating. The resulting DWC improved heat transfer performance of Al6061 significantly, 205%, as the dropwise condensates were rapidly eliminated from the surface. The variations on contact angle hysteresis before and after the steam condensation analysis revealed that the superhydrophobicity and DWC mode can be stably maintained under the steam condensing conditions.

Tribological properties of surface microtexture friction pairs under different lubrication conditions

In the field of journal bearings, the microtexture processing technology of the bush inner surface has become an effective way to improve the performance of journal bearing. The two-dimensional finite element model of microtexture surface with different shapes of friction pairs is established based on the Navier–Stokes (N-S) equation, and the effect of lubrication conditions on the frictional performance of friction pairs is analyzed. Four microtextures that are radial grooves, circular pits, local reticulation, and circumferential grooved microtexture are processed by laser microcarving on the surface of specimen, and three different lubricating medium conditions are set up with high-viscosity oil, low-viscosity oil, and oil–solid mixture, and the effect of lubrication condition and texture shape on the wear reduction of the microtexture friction pair is studied. Results show that the concave microtexture and the radial groove can improve effectively the friction performance of the friction pair. The microtexture can effectively store the lubricating medium and wear abrasive particles in the mixed lubrication, and avoid effectively the second wear, and its average friction coefficient of radial groove microtexture is 22%, 30% lower than that of high- and low-viscosity lubricating media, respectively. Both theory and experiment have proved that the effect of microtexture on high-viscosity lubricant is better than that of low-viscosity lubricant.

A 3D analysis of the onset of slip activity in relation to the degree of micro-texture in Ti–6Al–4V

The mechanical properties of titanium alloys result from their complex multi-scale microstructural features, including micron scale precipitates and millimeter scale microtextured regions (MTRs). While previous investigations have revealed that the presence of mm-scale MTRs can degrade mechanical properties, particularly fatigue, the accompanying strain localization processes that operate at the microscale within the α grains in MTRs are not well understood. The present work is a mechanistic investigation of MTRs using crystal plasticity simulations of mm3-scale experimentally captured and synthetically generated 3D microstructure datasets. The explicit modeling of both the α grains and MTRs in Ti–6Al–4V enables assessment of the effect of microtexture and local structure variations within the MTR on overall deformation behavior and the onset of plastic slip in MTRs. The presence of MTRs with a dominant [0001] orientation results in both stress and plastic strain hotspots during the early stages of straining. Crystal plasticity predictions are compared to previous digital image correlation studies on early strain localization. The influence of MTRs on the local stress and strain fields is discussed with regard to the monotonic tension, fatigue and dwell-fatigue behavior of titanium alloys.

Influence of MHD Lubrication and Textured Surface in EHL Line Contact

The present numerical study investigates the combined effect of micro-texture and magneto hydrodynamic lubrication behaviour on the performance of EHL line contact. Micro-textures are provided in the inlet zone of contacting surface has been studied. Modified Reynolds equation, elasticity equation and load balance equation has been solved using FEA and Generalized Minimal Residual Method (GMRES). A parametric study has been performed to optimize the micro-texture shapes in the contacting surfaces for different values of magneto hydrodynamic lubricant parameters The numerical results show that increasing externally applied magnetic field and micro- texture shapes enhances the values of performance parameter of EHL line contact. Finally, the variation in the steady-state EHL characteristics pertaining to unidirectional pure sliding contacts due to an artificially produced IZMTS is investigated numerically. The enhancement in central and minimum film thickness is found to be upto 38% and 28% respectively along with 33.28% reduction in coefficient of friction.

Effect of micro-textures on cutting fluid lubrication of cemented carbide tools

Severe friction at the cutter-chip interface increases tool surface wear and reduces tool life. The friction could be reduced by introducing cutting fluids between cutter and chip. The lubrication of cutting fluids depends on its penetration. The ability of cutting fluids to penetrate into the cutting zone can be enhanced by the surface texture of the cutters. In this paper, microgroove-liked textures with different groove width were fabricated on the rake-face of the cemented carbide YS8 cutters with femtosecond laser. The effect of micro-textures on the lubrication of cutting fluids in cutting zone was investigated in cutting H13 hot die steel tests with textured and non-textured cutters under full lubrication. Results showed that micro-textures enhanced penetration of the cutting fluid, improved the lubrication in the cutter-chip interface, and significantly reduced cutting force and tool wear compared to untextured tools. The micro-textured tool with groove width of 50 μm had the best performance among all tested tools. Mechanism responsible was found that cutting fluids can continuously penetrate into the cutting contact area through the sufficient space provided by the microgrooves on the rake-face.