Μm Surface Roughness Research Articles

Non-invasive Thermohydrodynamic Approach for Fast Cell Manipulation at the Microscale

Thermal gradients have emerged as a promising technique for manipulating and sorting biological material at the microscale, holding considerable potential in lab-on-a-chip technology. Herein, we propose a non-invasive thermohydrodynamic approach for fast cell manipulation using a microfluidic open-to-air device. Cell discrimination is achieved by simply changing the temperature gradient toward the control of the convective effect on their displacement. First, the size and morphology/roughness-based motion capabilities were modeled using polystyrene (PS) microparticles with different sizes (5 and 20 μm) and polycaprolactone (PCL) microspheres, respectively. Computational fluid dynamics simulations of the generated flow were also carried out to demonstrate the influence of both the thermohydrodynamic and Marangoni effects in the PS particle displacement, where the thermally induced convective effect was not enough to move the microparticles inside the channel, but the combination of thermally induced convection together with the Marangoni effect. Indeed, small particles (5 μm) followed a full convective path, whereas the bigger ones (20 μm) exhibited a rolling motion on the substrate from the cold side to the hot side. Also, the relationship between in-flow speed and PCL (≈ 20 μm) surface roughness confirmed the driving force of this convection-based approach. Then, the microfluidic device was successfully used to separate Henrietta Lacks cancer cells (HeLa) from red blood (RBCs) and fibroblast (HFF-1) cells. To this end, thermal gradients were tailored to achieve the desired thermohydrodynamic effect, showing a highly versatile performance. Both cell models (HeLa-RBCs and HeLa-HFF-1), due to rationale tweaking of the imposed temperature gradients (ΔT = 10 K, 303–293 K, and ΔT = 5 K, 303–298 K), were efficiently separated in less than 5 and 60 s, respectively; with excellent cell viabilities. The proposed microfluidic approach holds considerable promise for thermohydrodynamic sorting and manipulation of biological material by non-invasive methods using portable instrumentation. The potential parallelization of the thermal-convective approach opens new avenues for early disease diagnosis (liquid biopsies) or the study of biological systems, even at physiological temperatures with a potential impact in cell (organ)-on-a-chip technologies.

The effect of the anti-coagulant EDTA on the deposition and adhesion of whole blood deposits on non-porous substrates.

An investigation into whether the addition of a commonly used anti-coagulant agent like ethylenediaminetetraacetic acid (EDTA) has an impact on the adhesion potential of blood to non-porous substrates was conducted. Two non-porous substrates (aluminum and polypropylene) exhibiting six different surface roughness categories (R1-R6) were used as test substrates upon which either whole blood or blood treated with EDTA was deposited. Samples were exposed to different drying periods (24 hours, 48 hours, and 1 week) before undergoing a tapping agitation experiment in order to evaluate the adhesion to the surface. Clear differences in adhesion potential were observed between whole blood and blood treated with EDTA. Blood treated with EDTA displayed a stronger adhesion strength to aluminum after a drying time of 24 h pre-agitation, while whole blood presented with a stronger adhesion strength at the drying time of 48 h and 1 week. Both EDTA-treated and EDTA-untreated blood was shown to dislodge less easily on polypropylene with the only difference observed on smooth surfaces (0.51-1.50 μm surface roughness). Thus, when conducting transfer studies using smooth hydrophobic substrates like polypropylene or considering the likelihood of transfer given specific case scenarios, differences in adhesion strength of blood due to hydrophobic substrate characteristics and a decreased surface area need to be considered. Overall, whole blood displayed a better adhesion strength to aluminum, emphasizing that indirect transfer probability experiments using EDTA blood on substrates like aluminum should take an increased dislodgment tendency into account in their transfer estimations.

Influence of tool pin profile on the mechanical strength and surface roughness of AA6061-T6 overlap joint friction stir welding

This study presents the tensile strength and surface roughness resulting from friction stir welding (FSW) on the lap joint method using AA 6061 –T6. FSW is conducted by comparing three different tool pin shapes: hexagon, thread, and square. Overlap welding using the FSW method is challenging if machine parameters, such as spindle speed and feed rate, are incompatible. The experiment was conducted using a conventional milling machine with a spindle speed of 1400 -1750 rpm and a feed rate of 20 – 30 mm/min. The results show that a spindle speed of 1750 rpm and a feed rate of 30 mm/min using a square tool pin results in 83.5088 MPa ultimate tensile strength and 0.85 µm surface roughness (Ra), which is much better than hexagon and thread type tool pins. In addition, the overall results on all three tool pin shapes show that higher processing parameters increase tensile strength and surface roughness. This study revealed the effect of parameters on AA6061 –T6 and the resulting implications of mechanical strength and surface roughness.

Study on the Influence of Surface Integrity on Hydrogen Permeation Resistance of Hydrogen Production Reactor Materials

Hydrogen permeation reduces a material’s properties and increases the risk of brittle fracture, which causes a potential safety hazard. A workpiece’s hydrogen permeation resistance could be improved by improving its surface integrity through surface processing. This paper studies low-alloy steel’s surface integrity and its hydrogen permeation resistance in a hydrogen production reactor, using the electrochemical cathodic hydrogen-charging method to carry out electrochemical hydrogen-charging experiments. After the specimens were pretreated using different surface-grinding methods and shot peening pressure strengthening, they were hydrogen-charged on a self-designed and built electrolytic hydrogen charging platform. Before and after hydrogen charging, the specimens’ section hardness and tensile strength were tested, and the fracture morphology of the specimens was observed. The influence laws of surface roughness and surface residual compressive stress on the distribution of material hardness along the depth, the variation in material hardness, the fracture morphology, and the decline in the tensile properties of the low-alloy steel specimens after 5 h of hydrogen charging were analyzed. The reasons for the influence of surface integrity indexes on the hydrogen permeation resistance of the specimens were also analyzed. Based on the experimental results, a series of mechanical processing parameters were proposed to improve the material’s permeation resistance, which provides a theoretical and practical basis for the processing of materials with high surface integrity and hydrogen permeation resistance. Through the experiments, it was found that the hydrogen permeation resistance of the Ra 0.17 μm surface roughness specimen was the best of all specimens with different surface roughness values, and its hydrogen embrittlement sensitivity index was 20.96%. The specimen had the best hydrogen permeation resistance under 336 MPa surface residual compress stress, and its hydrogen embrittlement sensitivity index was 16.45%.

Dimensional Accuracy, Surface Roughness and Hardness Properties for Microplate Implants Manufacturing by EDM Die-Sinking Process

The high cost of manufacturing microplate implants is a primary issue. This is because the production of microplate implants uses the micro-milling and wire-EDM process. Production costs can be reduced using one machining process, and die-sinking EDM is an alternative in the manufacturing of microplate implants. This paper investigates the capability of EDM die-sinking in manufacturing microplate implants. This paper also studies the reaction of electrode materials and pulse currents to the microplate’s dimensional accuracy, surface roughness and hardness. The process of EDM die-sinking uses electrodes of graphite and copper with pulse current variance of 6, 9, and 13 A. The experiment results indicate that the process of EDM die-sinking success in manufacturing microplates on commercially pure titanium sheets. Decreasing the pulse current can improve dimensional accuracy, smoothen surface roughness and minimize the hardness decrease of the microplate. These results are better using the copper electrode compare with the graphite electrode. The best quality of the microplate is at 93.3% dimensional accuracy, 5.28 µm surface roughness, and a 12% decrease in hardness. The best quality microplates was achieved by using copper electrodes with a 6 A pulse current.

Slurryless electrochemical mechanical polishing of 4-inch 4H–SiC (0001) and (000–1) surfaces

Silicon carbide (SiC) is a very promising next-generation semiconductor material for power device applications, and polishing technology plays an important role in improving the performance of electronics. In this regard, slurryless electrochemical mechanical polishing (ECMP) is a promising polishing technology for SiC wafer in obtaining high efficiency and high precision. In this study, slurryless ECMP of 4-inch 4H–SiC (0001) and (000–1) surfaces (Si and C faces) were investigated aiming to the industrial application. Anodic oxidation property, polishing characteristics, and mechanism of the Si and C faces in slurryless ECMP were compared and clarified. Based on the obtained results, two-step slurryless ECMP (i.e., ECMP with diamond polishing plate and then with ceria polishing plate) was conducted on 4-inch as-sliced Si and C faces. Additionally, 4-inch Si and C faces with peak-to-valley (PV) value less than 2 μm and overall surface roughness in nanometer order were obtained.

Additive Manufacturing of WC-Co Specimens with Internal Channels.

Most material removal in modern manufacturing is currently performed using tools with indexable inserts. Additive manufacturing allows for the creation of new, experimental insert shapes and, more importantly, internal structures, such as channels for coolant. This study deals with developing a process for efficiently manufacturing WC-Co specimens with internal coolant channels with a focus on obtaining a suitable microstructure and surface finish, especially inside the channels. The first part of this study covers the development of process parameters to achieve a microstructure without cracks and with minimal porosity. The next stage focuses solely on improving the surface quality of the parts. Special attention is given to the internal channels, where true surface area and surface quality are evaluated, as these characteristics greatly influence coolant flow. To conclude, WC-Co specimens were successfully manufactured and a microstructure with low porosity and no cracks was achieved and an effective parameter set was found. We have developed a process that produces parts with a surface roughness comparable to those of standard SLS manufacturing of steel parts, while still providing a high-quality internal microstructure. The most suitable parameter set resulted in a profile surface roughness of Ra 4 μm and Rz 31 μm and areal surface roughness of Sa 7 µm and Sz 125 µm.

Effects of Tool Edge Geometry and Cutting Conditions on the Performance Indicators in Dry Turning AISI 1045 Steel

This article presents an experimental investigation and statistical analysis of the effects of cutting conditions on the machining performance of AISI 1045 steel using a wiper-shaped insert. Experimental findings are used to compare the machining performance obtained using wiper inserts with those obtained using conventional round-nose inserts as recently reported in the literature. In addition, the effects of process conditions, namely cutting speed, feed rate, and depth of cut, are analyzed in order to obtain optimum conditions for both types of inserts. The goal is to achieve the optimal machining outcomes: minimum surface roughness, resultant cutting force, and cutting temperature, but maximum material removal rate. A full factorial design was followed to conduct the experimental trials, while ANOVA was utilized to estimate the effect of each factor on the process responses. A desirability function optimization tool was used to optimize the studied responses. The results reveal that the optimum material removal rate for wiper-shaped inserts is 67% more than that of conventional inserts, while maintaining a 0.7 µm surface roughness value. The superior results obtained with wiper-shaped inserts allow wiper tools to use higher feed rates, resulting in larger material removal rates while obtaining the same surface quality.

Efficient surface polishing using burst and biburst mode ultrafast laser irradiation.

The use of laser irradiation for micromachining is widely applicable and has many benefits. One of the main uses is that it is possible to mill and polish the sample using the same laser system. State-of-the-art laser systems with high average optical power and burst regimes are widely used in technology. The main advantages of burst regimes are the closer fluence values to optimal fluences and residual heat reusage for subsequent pulses. In this study, the influence of MHz burst, GHz burst, and bibursts was investigated for significant surface polishing of copper and stainless-steel samples. Z-scan experiments were performed to determine the optimal number of sub-pulses inside the burst for the lowest surface roughness.

Nanoimprinting for all-polymer electro-optic waveguide devices

We performed the design and fabrication of polymer waveguide circuits, aiming for applications as electro-optic devices. Uniform waveguides with over one centimeter of length were fabricated by soft nanoimprint lithography. These multimode waveguides present a height of 3 µm and low surface roughness (2 nm), with a thin residual layer of 600 nm. Propagation losses at 1550 nm are estimated to be around 7 dB/cm.

A Novel Flushing Mechanism to Minimize Roughness and Dimensional Errors during Wire Electric Discharge Machining of Complex Profiles on Inconel 718.

One of the sustainability goals in the aeronautical industry includes developing cost-effective, high-performance engine components possessing complex curved geometries with excellent dimensional precision and surface quality. In this regard, several developments in wire electric discharge machining have been reported, but the influence of flushing attributes is not thoroughly investigated and is thus studied herein. The influence of four process variables, namely servo voltage, flushing pressure, nozzle diameter, and nozzle–workpiece distance, were analyzed on Inconel 718 in relation to geometrical errors (angular and radial deviations), spark gap formation, and arithmetic roughness. In this regard, thorough statistical and microscopical analyses are employed with mono- and multi-objective process optimization. The grey relational analysis affirms the reduction in the process’s limitations, validated through confirmatory experimentation results as 0.109 mm spark gap, 0.956% angular deviation, 3.49% radial deviation, and 2.2 µm surface roughness. The novel flushing mechanism improved the spark gap by 1.92%, reducing angular and radial deviations by 8.24% and 29.11%, respectively.

Investigation of the Surface Roughness and Surface Uniformity of a Hybrid Sandwich Structure after Machining.

The parameters of surface roughness Ra, Rz and Rmax as well as surface topography Sa, Sz, Sp and Sv of the two-layer sandwich structure composed of an AW-2024 T3 aluminum alloy (Al) and a carbon-fiber-reinforced polymer (CFRP) were measured to determine an impact of the machining configuration (arrangement of the materials forming a sandwich structure) and the type of tool (presence of the tool coating) on the quality of the surface obtained through circumferential milling. The measurements revealed that milling produced different values of surface roughness for the aluminum alloy and the CFRP composite with values of 2D and 3D surface roughness being higher for the composite layer. The highest value of Ra of 1.10 µm was obtained for the surface of the CFRP composite using the CFRP/Al configuration and a TiAlN-coated tool. The highest values of the Rz (6.51 µm) and Rmax (8.85 µm) surface roughness parameters were also obtained for the composite layer using the same machining configuration and type of tool.

Transfer Printable Single-Crystalline Coupons for III-V on Si Integration

The next-generation internet (6G) requires highly functional devices that e.g. realize frequencies in the THz range for higher data rates and lower latencies. Those requirements exceed the physical limits of established CMOS technologies based on silicon (Si). Hence, there is demand for other semiconductor materials with superior electronic and optical properties that complement Si. One of the key candidates is the III-V compound semiconductor, indium phosphide (InP). Due to its high electron mobility and direct band gap, InP-based devices allow access to frequencies >100 GHz and operate at the optical fibre compatible wavelength of 1.55 μm.1 With the perspective of leveraging the advantages of Si-based CMOS technology and III-V semiconductors, hetero-integration of III-V materials on Si is of great interest. However, existing integration approaches entail certain disadvantages: (i) High dislocation densities due to the lattice mismatch of InP and Si for integration via hetero-epitaxial growth;2 (ii) limited integration density and the requirement of accurate alignment for flip-chip integration; and (iii) high process-related losses of Si and III-V materials as well as thermal stress and low thermal conductivity of adhesive layers degrading device performance for wafer/die bonding technologies.3 Another promising approach for III-V-on-Si integration is micro-transfer-printing (μTP) that involves pick-up and transfer of µm-small chips from a source substrate to a target substrate with high alignment accuracy by using an elastomeric stamp. Advantages of μTP are high integration densities and efficient material use. The technique was already implemented for III-V-on-Si photonic integrated circuits by transfer of epitaxial III-V layers.4 However, using sacrificial III-V interlayers for release and adhesives for bonding still leads to transfer issues and low operation temperature for the devices, respectively.We pursue a new approach to hetero-integration of III-V on Si that aims at the transfer of single-crystalline InP coupons onto Si via μTP. This will be achieved by obtaining crystalline coupons with a thickness of d ≤ 10 µm and two polished surfaces that attain low roughness, needed i.a. for µTP. If the high structural quality of the single-crystalline InP source material can be maintained, this process will provide high quality templates for subsequent epitaxial growth. Towards this goal, we developed a sophisticated micro-preparation process in cooperation with the Leibniz Institute for High Performance Microelectronics IHP.5 Starting from 4-inch single crystals with homogeneous, low dislocation density of 2×103 cm- 2 grown at IKZ,6 thinned InP dies were obtained by sawing, grinding and employing an optimized two-step chemical mechanical polishing (CMP). In order to produce µm-sized transfer-printable coupons, the InP dies were micro structured by means of photolithography assisted patterning and wet (under-)etching (Fig. 1). The coupons can then be picked up with a stamp and transferred to the target wafer. Main innovation of this process is the resin which serves as low stress fixing layer for CMP as well as sacrificial layer for later release.The optimized CMP process with abrasive-free final polishing yielded InP platelets of the desired thickness below 10 μm with low thickness deviation < 1 µm and excellent surface roughness of S q ≈ 0.3 nm (Fig. 2a,b,d). This value even meets the requirements for adhesive-free bonding (S q ≤ 2 nm) and subsequent epitaxial growth (S q ≤ 0.5 nm). X-ray rocking curve mapping provides accurate spatial maps of lattice deformations in the material that may be a consequence of the mechanical processing. Rocking curve widths mappings of the 004 reflection of a (001) sample before and after thinning are homogeneous and below 25 arcsec in the majority of the sample area. Overall no signs of systematic crystal quality deterioration in the product platelets compared to bulk samples have been detected.In summary, the feasibility of μm-thin InP platelet fabrication was demonstrated. Final platelets meet the prerequisites of low and uniform thickness, high planarity, low roughness and little crystal quality deterioration. Furthermore, first InP platelets could successfully be patterned to 100–400 µm-sized coupons using optical lithography and wet etching (Fig. 2c). This opens a path to take the next steps towards hetero-integration on Si by means of µTP with high potential for adhesive-free bonding.

Study on dispersion and attenuation of laser-induced surface acoustic wave by grinding surface roughness

The dispersion and attenuation of surface acoustic wave (SAW) are important indicators for evaluating the damage of machined surface layer. However, the dispersion and attenuation of SAW is also affected by surface roughness. The finite element method can simulate the rough surface without surface damage. Based on the measured surface profiles of roughness profiler, a series of grinding surfaces of C45E steel with different surface roughness Ra are simulated by finite element method, and the dispersion and attenuation of laser-induced SAW are studied. It is found that with the increase of roughness Ra, the increase of dispersion is relatively uniform, while the increase of attenuation not. The possible reason is that the dispersion is mainly affected by the average amplitude of roughness, while the occasional deep valley profile has a great influence on the attenuation. Compared with the experimental data, it is found that the velocity variation of 10–40 MHz SAW caused by Ra 0.12–0.75 μm surface roughness accounts for 8%–19% of the total velocity variation, and the proportion increases with the increase of roughness. The attenuation of 15 MHz SAW caused by surface roughness accounts for 8%–13% of the total attenuation. For a rough surface, dispersion is approximately linear with the frequency of SAW, while the attenuation coefficient increases sharply with the increase of frequency. Therefore, it is necessary to first evaluate the influence of surface roughness, especially the influence on attenuation, when the dispersion and attenuation of SAW are used to evaluate the machined surface damage. The results of this paper can be used to evaluate the influence of roughness on the dispersion and attenuation of SAW, and reduce the deviation in the evaluation of machined surface damage.

Micro laser powder bed fusion of NiTi alloys with superior mechanical property and shape recovery function

Micro laser powder bed fusion (µ-LPBF) additive manufacturing presents enormous potential in fabricating complex metallic micro-components (i.e. the component with a feature size <100 µm). However, such fabricated parts often exhibit poor essential mechanical and functional properties. In this work, through rationally scaling down and coupling key processing parameters, various NiTi micro-components such as thin-wall structures and thin-strut lattices/stents are fabricated, which exhibiting superior manufacturing qualities and mechanical/functional properties to reported µ-LPBF prepared micro-components. The fabricated NiTi thin-wall structures not only achieve a minimum feature size of 52 µm and low surface roughness of < 2 µm, but also exhibit comparable tensile properties and better shape memory effect than conventional LPBF NiTi. The fabricated NiTi micro-lattices/stents with a strut diameter of ≤ 100 µm is shown to sustain up to 50% compressive deformation without mechanical failure and exhibits > 98% shape recovery upon heating. This study also reveals that across the thin wall, the µ-LPBF NiTi possesses unique melt pool morphology consisting of fan-shaped grains in the middle and near-vertical grains on side shoulders. At the microstructure level, it contains Ni 4 Ti 3 precipitates of generally smaller size than and dislocations of comparable volume density to the conventional LPBF NiTi. Besides, the µ-LPBF NiTi exhibits a wider phase transformation peak width and lower transformation latent heat than the conventional LPBF NiTi. These characteristics are resulted from the weak thermal cycle history experienced by the material during µ-LPBF processing which typically employs only single-track scanning mode.

Sustainable Manufacturing of Asymmetric Miniature-Sized Ratchet Wheels by Wire Electrical Discharge Machining

In this paper, the outcomes of an investigation conducted on the sustainable manufacturing of asymmetric rotary miniature-sized ratchet wheels of stainless steel (SS) 304 by a vertically traveling wire electrical discharge machining (WEDM) process are reported. The consumptions of energy and wire material are the process sustainability indicators considered in this work. Box-Behnken-based seventeen experiments were conducted by varying spark-on-time ‘Ton’, spark-off-time ‘Toff’, and wire rigidity ‘WT’. Desirability function analysis (DFA) based on multi-response optimization was performed to obtain an optimum setting of WEDM parameters to manufacture miniature-sized ratchet wheels with minimum energy and wire consumption. Sustainable manufacturing of ratchet wheels is performed at the optimum parameter combination of Ton-1.5 µs; Toff-40.5 µs; WT-1260 g, for the least values of energy consumption of 0.64 kWh and wire consumption of 20.11 g with no wire breakage and a significant reduction in total idle time. This ratchet wheel, manufactured at optimum parameters of WEDM, was also found to have a good finish (average surface roughness ‘Ra’-1.08 µm and maximum surface roughness ‘Rt’-6.81 µm) and defect-free tooth flank surfaces. Overall, it is concluded that WEDM has the potential to achieve sustainability in the manufacturing of miniature-sized ratchet wheels and other gears. The outcomes of this work will extensively facilitate engineers and researchers in selecting a suitable range of machining parameters for sustainable manufacturing of miniature-sized wheels and gears.

A new electrohydrodynamic printing method for patterns fabrication with low viscosity fluid of silicone oil

Abstract Silicone oil is a type of fluid with low viscosity, but it is not easy to form stable cone jet for electrohydrodynamic printing. In this paper, we proposed a new electrohydrodynamic printing method for patterns fabrication with this kind of low viscosity fluid. Dots array was first printed on the substrate at higher direct current voltage. Then by controlling the moving speed of the platform, the dots were connected into lines according to the fluidity of the silicone oil and its low surface tension. With the proposed method, the patterns with silicone oil can be successfully formed by electrohydrodynamic printing. In the experiment, the influence of main parameters including applied voltage, moving speed of substrate, distance from needle to substrate, and axial length of droplet on the quality of printed lines was studied. Finally, by optimizing the printing parameters, the silicone oil lines with width of 73 µm and low surface roughness were printed.

3D-printed porous Ti6Al4V alloys with silver coating combine osteocompatibility and antimicrobial properties

Additive manufacturing allows for the production of porous metallic implants for use in orthopaedics, providing excellent mechanical stability and osseointegration. However, the increased surface area of such porous implants also renders them susceptible to bacterial colonization. In this work, two trabecular porous Ti6Al4V alloys produced by electron beam melting were investigated for their osteocompatibility and antimicrobial effects, comparing samples with a silver-coated surface to uncoated samples. Dense grit-blasted Ti samples were used for comparison. The porous samples had pore sizes of 500–600 μm and 5 to 10 μm surface roughness, the silver-coated samples contained 7 at.% Ag, resulting in a cumulative Ag release of 3.5 ppm up to 28 days. Silver reduced the adhesion of Staphylococcus aureus to porous samples and inhibited 72 h biofilm formation by Staphylococcus epidermidis but not that of S. aureus. Primary human osteoblast adhesion, proliferation and differentiation were not impaired in the presence of silver, and expression of osteogenic genes as well as production of mineralized matrix were similar on silver-coated and uncoated samples. Our findings indicate that silver coating of porous titanium implants can achieve antimicrobial effects without compromising osteocompatibility, but higher silver contents may be needed to yield a sustained protection against fast-growing bacteria.

Surface morphology and microstructural analysis of al 8081-mg/zr/tio2 nano metal matrix composite – A base for performance evaluation of polycrystalline diamond and poly cubic boron nitride tools

The investigation of surface roughness in machined materials/products has proven to be a difficult undertaking. The surface quality is determined not only by the parameters but also by the cutting conditions. Surprisingly, a study indicated that when analysing the quality of machining processes currently being done, surface morphology has a significant impact on tool performance. PCD (Polycrystalline diamond) and PCBN (Poly cubic boron nitride) cutting tools produce a better surface finish, which is explored in the machining of Al-Mg/Zr/TiO2 (15%), nano metal matrix composites (NMMC). The study primarily focuses on determining the best parameters for end milling NMMCs in tests for long-term production sustainability. Using scanning electron microscopy, microstructural study of the machined surface will aid in finding the parameters responsible for the cause of surface integrity. The work focusses on analysing tool performance by monitoring the machining process in real time using signal characteristics, forecasting vibrations (displacement) and machine outputs using surface topography and chip analysis. The tool failure was acquired by establishing a correlation between displacement (vibrations) and post machining outcome of experimental study, as a result, the evolution of displacement in the PCBN tool is 24.7 μm, which is better compared to 34.3 μm in the PCD tool at 3000 r/min. PCBN outperformed PCD with a 1.82 μm surface roughness, resulting in longer tool life. Thus, this economical reliable empirical method the problem of finding difficulty identifying the causing of tool wear and failure by correlating sensor signals features with experimental results.

Micro-electrochemical jet machining of large area microtexturing with tool movement strategy

ABSTRACT Microtextured surfaces, particularly circular micropattern, significantly enhance the function and performance of microfabricated devices and engineering parts. A distinctive and inventive concept of maskless microelectrochemical jet machining (EJM) is utilized for producing the microcircular pattern over large area. In this research work, an advanced concept, i.e. maskless micro-EJM is presented to produce the microtextures on large area using the reusable masked tool movement strategy on stainless steel. One masked patterned tool can fabricate many high-quality micropatterned samples over large area using the tool movement strategy. High-pressure electrolyte flow through textured tool is developed to acquire the high-quality microtextures with controlled dimensions. The machining consequence of substantial input parameters, i.e. IEG, flow rate and frequency on microdimpled characteristics such as MRR, overcut, depth, and R a is explored. Microdimples of 5.3 mg/min MRR, 20.07 µm overcut, 13.5 µm depth, and 0.0601 µm surface roughness and 5.29 cm2 machining area are successfully fabricated using the reusable masked tool. The present study confirms that it is achievable to acquire the large area microtexturing using this innovative technique.